Anti-LRP5 antibodies and methods of use

ABSTRACT

The invention provides anti-LRP5 antibodies and methods of making and using the same.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.13/744,766, filed on Jan. 18, 2013, and which claims benefit under 35U.S.C. 119 to U.S. Provisional Application No. 61/588,100, filed on Jan.18, 2012, the entire contents of which are incorporated herein byreference.

This application contains a Sequence Listing submitted via EFS-Web andhereby incorporated by reference in its entirety. Said ASCII copy,created on Oct. 8, 2015, is named P04855-US-2_SequenceListing.txt and is44,971 bytes in size.

FIELD OF THE INVENTION

The present invention relates to anti-LRP5 antibodies and methods ofusing the same.

BACKGROUND

It is now well established that angiogenesis is an important contributorto the pathogenesis of a variety of disorders. These include solidtumors and metastasis, intraocular neovascular diseases such asretinopathies, e.g., diabetic retinopathy, retinal vein occlusion (RVO),wet age-related macular degeneration (AMD), neovascular glaucoma, immunerejection of transplanted corneal tissue and other tissues, andrheumatoid arthritis. Duda et al. J. Clin. Oncology 25(26): 4033-42(2007); Kesisis et al. Curr. Pharm. Des. 13: 2795-809 (2007); Zhang & MaProg. Ret. & Eye Res. 26: 1-37 (2007).

The retina receives its blood supply from retinal vessels, which supplythe inner part of the retina, and choroidal vessels, which supply theouter part. Damage to retinal vessels occurs in several diseaseprocesses including diabetic retinopathy, retinopathy of prematurity,and central and branched retinal vein occlusions (ischemicretinopathies). Retinal ischemia from this damage results in undesirableneovascularization. Choroidal neovascularization occurs in a number ofother disease processes, including AMD. In contrast, incompletevascularization of the retina is a hallmark in patients with certaingenetic diseases, e.g. familial exudative vitreoretinopathy (FEVR),Coats' disease, and Norrie disease caused by mutation of the Wntreceptor Frizzled4 (Fzd4), the co-receptor LRP5 or the secreted ligandNorrin (Berger et al. Nature Genet. 1:199-203 (1992); Chen et al. NatureGenet. 1:204-208 (1992); Robitaille et al. Nature Genet. 32:326-30(2002); Toomes et al. Am. J. Hum. Genet. 74:721-30 (2004)). Anadditional protein, TSPAN12, has been shown to be involved in Norrinsignaling (Junge et al. Cell 139:299-311 (2009) and WO 2010/030813).Mutations in the Tspan12 gene are also reported to be causal for FEVR(Poulter et al. Invest Ophthalmol Vis Sci. 14; 53(6):2873-9 (2012); Yanget al. Molecular Vision 17:1128-1135 (2011); Poulter et al. The AmericanJournal of Human Genetics 86, 248-253 (2010)). Models for these geneticdiseases are available in mice knocked out for the correspondinghomologous genes.

Despite the many advances in the field of ocular angiogenesis, thereremains a need to identify targets and develop means that can supplementor enhance the efficacy of existing therapies.

SUMMARY

The invention provides anti-LRP5 antibodies and methods of making andusing the same, particularly in the treatment of conditions and diseasesassociated with angiogenesis.

In one aspect, the invention provides an isolated antibody that binds toLow-density lipoprotein receptor-related protein 5 (LRP5), wherein theantibody potentiates Norrin activity and/or Norrin/Fzd4 signaling. Insome embodiments, the antibody is a monoclonal antibody. In someembodiments the antibody is a human, humanized, or chimeric antibody. Insome embodiments, the antibody is an antibody fragment that binds LRP5.

In some embodiments, the antibody comprises (a) HVR-H3 comprising theamino acid sequence YYRYAPYRSLGMDV (SEQ ID NO: 23) orWIPQSYPFX₁SYKSGFDY, wherein X₁ is A or R (SEQ ID NO: 24), (b) HVR-L3comprising the amino acid sequence QQYYX₁YPFT, wherein X₁ is L or S (SEQID NO: 25), and (c) HVR-H2 comprising the amino acid sequenceGX₁ISX₂X₃GX₄STYYADSVKG, wherein X₁ is A or G, X₂ is A or S, X₃ is P orS, X₄ is S or W (SEQ ID NO: 26), or SRISSNGGSTYYADSVKG (SEQ ID NO: 27).In some embodiments, the antibody comprises (a) HVR-H1 comprising theamino acid sequence GFTFSSYAMX₁, wherein X₁ is H or S (SEQ ID NO: 28),(b) HVR-H2 comprising the amino acid sequence GX₁ISX₂X₃GX₄STYYADSVKG,wherein X₁ is A or G, X₂ is A or S, X₃ is P or S, X₄ is S or W (SEQ IDNO: 26), or SRISSNGGSTYYADSVKG (SEQ ID NO: 27) and (c) HVR-H3 comprisingthe amino acid sequence YYRYAPYRSLGMDV (SEQ ID NO: 23) orWIPQSYPFX₁SYKSGFDY, wherein X₁ is A or R (SEQ ID NO: 24). In someembodiments, the antibody further comprises (a) HVR-L1 comprising theamino acid sequence RASQGISSYLA (SEQ ID NO: 29) or RASQX₁X₂X₃X₄YLA,wherein X₁ is A, G, S or V, X₂ is I or M, X₃ is F, G, S or Y, and X₄ isG, S or Y (SEQ ID NO: 30); (b) HVR-L2 comprising the amino acid sequenceAASSLQS (SEQ ID NO: 31) or DASX₁X₂ES, wherein X₁ is S or T and X₂ is Lor R (SEQ ID NO: 32); and (c) HVR-L3 comprising the amino acid sequenceQQYYX₁YPFT, wherein X₁ is L or S (SEQ ID NO: 33). In some embodiments,the antibody comprises (a) HVR-L1 comprising the amino acid sequenceRASQGISSYLA (SEQ ID NO: 29) or RASQX₁X₂X₃X₄YLA, wherein X₁ is A, G, S orV, X₂ is I or M, X₃ is G, F, Y or S, and X₄ is G, Y or S (SEQ ID NO:30); (b) HVR-L2 comprising the amino acid sequence AASSLQS (SEQ ID NO:31) or DASX₁X₂ES, wherein X₁ is S or T and X₂ is L or R (SEQ ID NO: 32);and (c) HVR-L3 comprising the amino acid sequence QQYYX₁YPFT, wherein X₁is L or S (SEQ ID NO: 33). In some embodiments, the antibody comprisesone or more heavy chain variable domain framework sequences selectedfrom the group consisting of SEQ ID NO: 34-37. In some embodiments, theantibody comprises (a) a VH sequence having at least 95% sequenceidentity to the amino acid sequence of one of SEQ ID NOs: 1 to 11; (b) aVL sequence having at least 95% sequence identity to the amino acidsequence of one of SEQ ID NOs: 12 to 22; or (c) a VH sequence as in (a)and a VL sequence as in (b). In some embodiments, the antibody comprisesa VH sequence of one of SEQ ID NOs: 1 to 11. In some embodiments, theantibody comprises a VL sequence of one of SEQ ID NOs: 12 to 22. In someembodiments, the antibody comprises a VH sequence of one of SEQ ID NOs:1 to 11 and a VL sequence of one of SEQ ID NOs: 12 to 22. In someembodiments, the antibody comprises the VH and VL sequences of anantibody show in FIGS. 4 and 5. In some embodiments, the antibody is afull length IgG1 antibody.

In another aspect, the invention provides isolated nucleic acid encodingan antibody of the invention. In some embodiments, the inventionprovides a host cell comprising the nucleic acid of claim 15. In someembodiments, the invention provides a method of producing an antibodycomprising culturing the host cell of claim 16 so that the antibody isproduced. In some embodiments, the method further comprises recoveringthe antibody from the host cell.

In some embodiments, the invention provides an immunoconjugatecomprising an antibody of the invention and a cytotoxic agent. In someembodiments, the invention provides a pharmaceutical formulationcomprising an antibody of the invention and a pharmaceuticallyacceptable carrier. In some embodiments, the pharmaceutical formulationfurther comprises an additional therapeutic agent, e.g. a VEGFantagonist (including, e.g., an anti-VEGF antibody or antibody fragment,e.g. ranibizumab, a soluble VEGF receptor, e.g. aflibercept, or anaptamer, e.g. pegaptanib), a TSPAN12 agonist, plasmin, plasminogen,tissue plasminogen activator, a TNF-α inhibitor, and/or a steroid, e.g.triamcinolone or dexamethasone.

In some embodiments, the invention provides an antibody of the inventionfor use as a medicament. In some embodiments, the invention provides anantibody of the invention for use in treating a retinopathy includingproliferative diabetic retinopathy, CNV, AMD, diabetic and otherischemia-related retinopathies, DME, pathological myopia, vonHippel-Lindau disease, histoplasmosis of the eye, CRVO, BRVO, cornealneovascularization, retinal neovascularization, ROP, FEVR, Coats'disease, Norrie Disease, OPPG (Osteporosis-Pseudoglioma Syndrome),subconjunctival hemorrhage, or hypertensive retinopathy. In someembodiments, the invention provides an antibody of the invention for usein potentiating Norrin activity and/or Norrin/Fzd4 signaling. In someembodiments, the invention provides an antibody of the invention for usein the manufacture of a medicament. In some embodiments, the medicamentis for treatment of a retinopathy including proliferative diabeticretinopathy, CNV, AMD, diabetic and other ischemia-relatedretinopathies, DME, pathological myopia, von Hippel-Lindau disease,histoplasmosis of the eye, CRVO, BRVO, corneal neovascularization,retinal neovascularization, ROP, FEVR, Coats' disease, Norrie Disease,OPPG (Osteporosis-Pseudoglioma Syndrome), subconjunctival hemorrhage, orhypertensive retinopathy. In some embodiments, the medicament is forpotentiating Norrin activity and/or Norrin/Fzd4 signaling.

In some embodiments, the invention provides a method of treating anindividual having a retinopathy including proliferative diabeticretinopathy, CNV, AMD, diabetic and other ischemia-relatedretinopathies, DME, pathological myopia, von Hippel-Lindau disease,histoplasmosis of the eye, CRVO, BRVO, corneal neovascularization,retinal neovascularization, ROP, FEVR, Coats' disease, Norrie Disease,OPPG (Osteporosis-Pseudoglioma Syndrome), subconjunctival hemorrhage, orhypertensive retinopathy comprising administering to the individual aneffective amount of an antibody of the invention. In some embodiments,the method further comprises administering to the individual aneffective amount of an additional therapeutic agent, e.g. a VEGFantagonist (including, e.g., an anti-VEGF antibody or antibody fragment,e.g. ranibizumab, a soluble VEGF receptor, e.g. aflibercept, or anaptamer, e.g. pegaptanib), a recombinant NORRIN protein, a TSPAN12agonist, plasmin, plasminogen, tissue plasminogen activator, a TNF-αinhibitor, and/or a steroid, e.g. triamcinolone or dexamethasone. Insome embodiments, the invention provides a method of potentiating Norrinactivity and/or Norrin/Fzd4 signaling in an individual comprisingadministering to the individual an effective amount of an antibody ofthe invention to potentiate Norrin activity and/or Norrin/Fzd4signaling. In some embodiments, the invention provides a method ofrescuing a signaling defect in an individual caused by mutation inNorrin and/or Fzd4 comprising administering the antibody of claim 1.

BRIEF DESCRIPTION OF THE FIGURES

FIGS. 1A and 1B show that anti-LRP5 antibodies potentiateNorrin/Fzd4-mediated signaling and rescue Fzd4_(M157V) mutation. In thisFigure the prefix “P6C” is used, whereas in other places in thespecification “YW629” is used interchangeably.

FIGS. 2A and 2B show that anti-LRP5 antibodies potentiate Norrinactivity and rescue loss of Tspan12 in human retinal endothelialmicrovascular cells (HREMVC). In this Figure the prefix “P6C” is used,whereas in other places in the specification “YW629” is usedinterchangeably.

FIGS. 3A and 3B show that an anti-LRP5 antibody partially rescuesvascular defects in Tspan12 knockout mice. In this Figure the prefix“P6C” is used, whereas in other places in the specification “YW629” isused interchangeably.

FIGS. 4A and 4B show the heavy chain variable region sequences forvarious anti-LRP5 antibodies with CDR-H1, CDR-H2, and CDR-H3 boxed. Thecorresponding SEQ ID NOs: for these sequences are as follows: YW629.42(SEQ ID NO: 1), YW629.42.57 (SEQ ID NO: 2), YW629.42.58 (SEQ ID NO: 3),YW629.42.65 (SEQ ID NO: 4), YW629.51 (SEQ ID NO: 5), YW629.51.13 (SEQ IDNO: 6), YW629.51.61 (SEQ ID NO: 7), YW629.51.63 (SEQ ID NO: 8),YW629.51.77 (SEQ ID NO: 9), YW629.51.78 (SEQ ID NO: 10), and YW629.51.80(SEQ ID NO: 11).

FIGS. 5A and 5B show the light chain variable region sequences forvarious anti-LRP5 antibodies with CDR-L1, CDR-L2, and CDR-L3 boxed. Thecorresponding SEQ ID NOs: for these sequences are as follows: YW629.42(SEQ ID NO: 12), YW629.42.57 (SEQ ID NO: 13), YW629.42.58 (SEQ ID NO:14), YW629.42.65 (SEQ ID NO: 15), YW629.51 (SEQ ID NO: 16), YW629.51.13(SEQ ID NO: 17), YW629.51.61 (SEQ ID NO: 18), YW629.51.63 (SEQ ID NO:19), YW629.51.77 (SEQ ID NO: 20), YW629.51.78 (SEQ ID NO: 21), andYW629.51.80 (SEQ ID NO: 22).

FIGS. 6A and 6B show that an anti-LRP5 antibody partially rescuesretinal vascular defects associated with Tspan12 knockout.

FIGS. 7A-7C show that an anti-LRP5 antibody promotes vascular regrowthand reduces pathologic angiogenesis in the oxygen induced retinopathymodel of vascular retinal disease.

FIGS. 8A-8C show that an anti-LRP5 antibody potentiates Norrin and Wnt7bsignaling, but while antagonizing Wnt3a signaling.

FIGS. 9A and 9B show that an anti-LRP5 antibody rescues the signalingdefect of mutations in ligand or receptor component that reduce receptorclustering.

FIGS. 10A and 10B show that antibody bivalency is required for anti-LRP5antibody-mediated potentiation of Norrin signaling, but not inhibitionof Wnt3a signaling.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION I. Definitions

An “acceptor human framework” for the purposes herein is a frameworkcomprising the amino acid sequence of a light chain variable domain (VL)framework or a heavy chain variable domain (VH) framework derived from ahuman immunoglobulin framework or a human consensus framework, asdefined below. An acceptor human framework “derived from” a humanimmunoglobulin framework or a human consensus framework may comprise thesame amino acid sequence thereof, or it may contain amino acid sequencechanges. In some embodiments, the number of amino acid changes are 10 orless, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less,3 or less, or 2 or less. In some embodiments, the VL acceptor humanframework is identical in sequence to the VL human immunoglobulinframework sequence or human consensus framework sequence.

“Affinity” refers to the strength of the sum total of noncovalentinteractions between a single binding site of a molecule (e.g., anantibody) and its binding partner (e.g., an antigen). Unless indicatedotherwise, as used herein, “binding affinity” refers to intrinsicbinding affinity which reflects a 1:1 interaction between members of abinding pair (e.g., antibody and antigen). The affinity of a molecule Xfor its partner Y can generally be represented by the dissociationconstant (Kd). Affinity can be measured by common methods known in theart, including those described herein. Specific illustrative andexemplary embodiments for measuring binding affinity are described inthe following.

An “affinity matured” antibody refers to an antibody with one or morealterations in one or more hypervariable regions (HVRs), compared to aparent antibody which does not possess such alterations, suchalterations resulting in an improvement in the affinity of the antibodyfor antigen.

The terms “anti-LRP5 antibody” and “an antibody that binds to LRP5”refer to an antibody that is capable of binding LRP5 with sufficientaffinity such that the antibody is useful as a diagnostic and/ortherapeutic agent in targeting LRP5. In one embodiment, the extent ofbinding of an anti-LRP5 antibody to an unrelated, non-LRP5 protein isless than about 10% of the binding of the antibody to LRP5 as measured,e.g., by a radioimmunoassay (RIA). In certain embodiments, an antibodythat binds to LRP5 has a dissociation constant (Kd) of ≦1 μM, ≦100 nM,≦10 nM, ≦1 nM, ≦0.1 nM, ≦0.01 nM, or ≦0.001 nM (e.g. 10⁻⁸ M or less,e.g. from 10⁻⁸ M to 10⁻¹³ M, e.g., from 10⁻⁹ M to 10⁻¹³ M). In certainembodiments, an anti-LRP5 antibody binds to an epitope of LRP5 that isconserved among LRP5 from different species.

The term “antibody” herein is used in the broadest sense and encompassesvarious antibody structures, including but not limited to monoclonalantibodies, polyclonal antibodies, multispecific antibodies (e.g.,bispecific antibodies), and antibody fragments so long as they exhibitthe desired antigen-binding activity.

An “antibody fragment” refers to a molecule other than an intactantibody that comprises a portion of an intact antibody that binds theantigen to which the intact antibody binds. Examples of antibodyfragments include but are not limited to Fv, Fab, Fab′, Fab′-SH,F(ab′)₂; diabodies; linear antibodies; single-chain antibody molecules(e.g. scFv); and multispecific antibodies formed from antibodyfragments.

An “antibody that binds to the same epitope” as a reference antibodyrefers to an antibody that blocks binding of the reference antibody toits antigen in a competition assay by 50% or more, and conversely, thereference antibody blocks binding of the antibody to its antigen in acompetition assay by 50% or more. An exemplary competition assay isprovided herein.

The term “chimeric” antibody refers to an antibody in which a portion ofthe heavy and/or light chain is derived from a particular source orspecies, while the remainder of the heavy and/or light chain is derivedfrom a different source or species.

The “class” of an antibody refers to the type of constant domain orconstant region possessed by its heavy chain. There are five majorclasses of antibodies: IgA, IgD, IgE, IgG, and IgM, and several of thesemay be further divided into subclasses (isotypes), e.g., IgG₁, IgG₂,IgG₃, IgG₄, IgA₁, and IgA₂. The heavy chain constant domains thatcorrespond to the different classes of immunoglobulins are called α, δ,ε, γ, and μ, respectively.

The term “cytotoxic agent” as used herein refers to a substance thatinhibits or prevents a cellular function and/or causes cell death ordestruction. Cytotoxic agents include, but are not limited toradioactive isotopes (e.g., At²¹¹, I¹³¹, I¹²⁵, Y⁹⁰, Re¹⁸⁶, Re¹⁸⁸, Sm¹⁵³,Bi²¹², P³², Pb²¹² and radioactive isotopes of Lu); chemotherapeuticagents or drugs (e.g., methotrexate, adriamicin, vinca alkaloids(vincristine, vinblastine, etoposide), doxorubicin, melphalan, mitomycinC, chlorambucil, daunorubicin or other intercalating agents); growthinhibitory agents; enzymes and fragments thereof such as nucleolyticenzymes; antibiotics; toxins such as small molecule toxins orenzymatically active toxins of bacterial, fungal, plant or animalorigin, including fragments and/or variants thereof; and the variousantitumor or anticancer agents disclosed below.

“Effector functions” refer to those biological activities attributableto the Fc region of an antibody, which vary with the antibody isotype.Examples of antibody effector functions include: C1q binding andcomplement dependent cytotoxicity (CDC); Fc receptor binding;antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g. B cell receptor); and B cellactivation.

An “effective amount” of an agent, e.g., a pharmaceutical formulation,refers to an amount effective, at dosages and for periods of timenecessary, to achieve the desired therapeutic or prophylactic result.

The term “Fc region” herein is used to define a C-terminal region of animmunoglobulin heavy chain that contains at least a portion of theconstant region. The term includes native sequence Fc regions andvariant Fc regions. In one embodiment, a human IgG heavy chain Fc regionextends from Cys226, or from Pro230, to the carboxyl-terminus of theheavy chain. However, the C-terminal lysine (Lys447) of the Fc regionmay or may not be present. Unless otherwise specified herein, numberingof amino acid residues in the Fc region or constant region is accordingto the EU numbering system, also called the EU index, as described inKabat et al., Sequences of Proteins of Immunological Interest, 5th Ed.Public Health Service, National Institutes of Health, Bethesda, Md.,1991.

“Framework” or “FR” refers to variable domain residues other thanhypervariable region (HVR) residues. The FR of a variable domaingenerally consists of four FR domains: FR1, FR2, FR3, and FR4.Accordingly, the HVR and FR sequences generally appear in the followingsequence in VH (or VL): FR1-H1(L1)-FR2-H2(L2)-FR3-H3(L3)-FR4.

The terms “full length antibody,” “intact antibody,” and “wholeantibody” are used herein interchangeably to refer to an antibody havinga structure substantially similar to a native antibody structure orhaving heavy chains that contain an Fc region as defined herein.

The terms “host cell,” “host cell line,” and “host cell culture” areused interchangeably and refer to cells into which exogenous nucleicacid has been introduced, including the progeny of such cells. Hostcells include “transformants” and “transformed cells,” which include theprimary transformed cell and progeny derived therefrom without regard tothe number of passages. Progeny may not be completely identical innucleic acid content to a parent cell, but may contain mutations. Mutantprogeny that have the same function or biological activity as screenedor selected for in the originally transformed cell are included herein.

A “human antibody” is one which possesses an amino acid sequence whichcorresponds to that of an antibody produced by a human or a human cellor derived from a non-human source that utilizes human antibodyrepertoires or other human antibody-encoding sequences. This definitionof a human antibody specifically excludes a humanized antibodycomprising non-human antigen-binding residues.

A “human consensus framework” is a framework which represents the mostcommonly occurring amino acid residues in a selection of humanimmunoglobulin VL or VH framework sequences. Generally, the selection ofhuman immunoglobulin VL or VH sequences is from a subgroup of variabledomain sequences. Generally, the subgroup of sequences is a subgroup asin Kabat et al., Sequences of Proteins of Immunological Interest, FifthEdition, NIH Publication 91-3242, Bethesda Md. (1991), vols. 1-3. In oneembodiment, for the VL, the subgroup is subgroup kappa I as in Kabat etal., supra. In one embodiment, for the VH, the subgroup is subgroup IIIas in Kabat et al., supra.

A “humanized” antibody refers to a chimeric antibody comprising aminoacid residues from non-human HVRs and amino acid residues from humanFRs. In certain embodiments, a humanized antibody will comprisesubstantially all of at least one, and typically two, variable domains,in which all or substantially all of the HVRs (e.g., CDRs) correspond tothose of a non-human antibody, and all or substantially all of the FRscorrespond to those of a human antibody. A humanized antibody optionallymay comprise at least a portion of an antibody constant region derivedfrom a human antibody. A “humanized form” of an antibody, e.g., anon-human antibody, refers to an antibody that has undergonehumanization.

The term “hypervariable region” or “HVR,” as used herein, refers to eachof the regions of an antibody variable domain which are hypervariable insequence and/or form structurally defined loops (“hypervariable loops”).Generally, native four-chain antibodies comprise six HVRs; three in theVH (H1, H2, H3), and three in the VL (L1, L2, L3). HVRs generallycomprise amino acid residues from the hypervariable loops and/or fromthe “complementarity determining regions” (CDRs), the latter being ofhighest sequence variability and/or involved in antigen recognition.Exemplary hypervariable loops occur at amino acid residues 26-32 (L1),50-52 (L2), 91-96 (L3), 26-32 (H1), 53-55 (H2), and 96-101 (H3).(Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987).) Exemplary CDRs(CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2, and CDR-H3) occur at amino acidresidues 24-34 of L1, 50-56 of L2, 89-97 of L3, 31-35B of H1, 50-65 ofH2, and 95-102 of H3. (Kabat et al., Sequences of Proteins ofImmunological Interest, 5th Ed. Public Health Service, NationalInstitutes of Health, Bethesda, Md. (1991).) With the exception of CDR1in VH, CDRs generally comprise the amino acid residues that form thehypervariable loops. CDRs also comprise “specificity determiningresidues,” or “SDRs,” which are residues that contact antigen. SDRs arecontained within regions of the CDRs called abbreviated-CDRs, or a-CDRs.Exemplary a-CDRs (a-CDR-L1, a-CDR-L2, a-CDR-L3, a-CDR-H1, a-CDR-H2, anda-CDR-H3) occur at amino acid residues 31-34 of L1, 50-55 of L2, 89-96of L3, 31-35B of H1, 50-58 of H2, and 95-102 of H3. (See Almagro andFransson, Front. Biosci. 13:1619-1633 (2008).) Unless otherwiseindicated, HVR residues and other residues in the variable domain (e.g.,FR residues) are numbered herein according to Kabat et al., supra.

An “immunoconjugate” is an antibody conjugated to one or moreheterologous molecule(s), including but not limited to a cytotoxicagent.

An “individual” or “subject” is a mammal. Mammals include, but are notlimited to, domesticated animals (e.g., cows, sheep, cats, dogs, andhorses), primates (e.g., humans and non-human primates such as monkeys),rabbits, and rodents (e.g., mice and rats). In certain embodiments, theindividual or subject is a human.

An “isolated” antibody is one which has been separated from a componentof its natural environment. In some embodiments, an antibody is purifiedto greater than 95% or 99% purity as determined by, for example,electrophoretic (e.g., SDS-PAGE, isoelectric focusing (IEF), capillaryelectrophoresis) or chromatographic (e.g., ion exchange or reverse phaseHPLC). For review of methods for assessment of antibody purity, see,e.g., Flatman et al., J. Chromatogr. B 848:79-87 (2007).

An “isolated” nucleic acid refers to a nucleic acid molecule that hasbeen separated from a component of its natural environment. An isolatednucleic acid includes a nucleic acid molecule contained in cells thatordinarily contain the nucleic acid molecule, but the nucleic acidmolecule is present extrachromosomally or at a chromosomal location thatis different from its natural chromosomal location.

“Isolated nucleic acid encoding an anti-LRP5 antibody” refers to one ormore nucleic acid molecules encoding antibody heavy and light chains (orfragments thereof), including such nucleic acid molecule(s) in a singlevector or separate vectors, and such nucleic acid molecule(s) present atone or more locations in a host cell.

The term “monoclonal antibody” as used herein refers to an antibodyobtained from a population of substantially homogeneous antibodies,i.e., the individual antibodies comprising the population are identicaland/or bind the same epitope, except for possible variant antibodies,e.g., containing naturally occurring mutations or arising duringproduction of a monoclonal antibody preparation, such variants generallybeing present in minor amounts. In contrast to polyclonal antibodypreparations, which typically include different antibodies directedagainst different determinants (epitopes), each monoclonal antibody of amonoclonal antibody preparation is directed against a single determinanton an antigen. Thus, the modifier “monoclonal” indicates the characterof the antibody as being obtained from a substantially homogeneouspopulation of antibodies, and is not to be construed as requiringproduction of the antibody by any particular method. For example, themonoclonal antibodies to be used in accordance with the presentinvention may be made by a variety of techniques, including but notlimited to the hybridoma method, recombinant DNA methods, phage-displaymethods, and methods utilizing transgenic animals containing all or partof the human immunoglobulin loci, such methods and other exemplarymethods for making monoclonal antibodies being described herein.

A “naked antibody” refers to an antibody that is not conjugated to aheterologous moiety (e.g., a cytotoxic moiety) or radiolabel. The nakedantibody may be present in a pharmaceutical formulation.

“Native antibodies” refer to naturally occurring immunoglobulinmolecules with varying structures. For example, native IgG antibodiesare heterotetrameric glycoproteins of about 150,000 daltons, composed oftwo identical light chains and two identical heavy chains that aredisulfide-bonded. From N- to C-terminus, each heavy chain has a variableregion (VH), also called a variable heavy domain or a heavy chainvariable domain, followed by three constant domains (CH1, CH2, and CH3).Similarly, from N- to C-terminus, each light chain has a variable region(VL), also called a variable light domain or a light chain variabledomain, followed by a constant light (CL) domain. The light chain of anantibody may be assigned to one of two types, called kappa (κ) andlambda (λ), based on the amino acid sequence of its constant domain.

The term “package insert” is used to refer to instructions customarilyincluded in commercial packages of therapeutic products, that containinformation about the indications, usage, dosage, administration,combination therapy, contraindications and/or warnings concerning theuse of such therapeutic products.

“Percent (%) amino acid sequence identity” with respect to a referencepolypeptide sequence is defined as the percentage of amino acid residuesin a candidate sequence that are identical with the amino acid residuesin the reference polypeptide sequence, after aligning the sequences andintroducing gaps, if necessary, to achieve the maximum percent sequenceidentity, and not considering any conservative substitutions as part ofthe sequence identity. Alignment for purposes of determining percentamino acid sequence identity can be achieved in various ways that arewithin the skill in the art, for instance, using publicly availablecomputer software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR)software. Those skilled in the art can determine appropriate parametersfor aligning sequences, including any algorithms needed to achievemaximal alignment over the full length of the sequences being compared.For purposes herein, however, % amino acid sequence identity values aregenerated using the sequence comparison computer program ALIGN-2. TheALIGN-2 sequence comparison computer program was authored by Genentech,Inc., and the source code has been filed with user documentation in theU.S. Copyright Office, Washington D.C., 20559, where it is registeredunder U.S. Copyright Registration No. TXU510087. The ALIGN-2 program ispublicly available from Genentech, Inc., South San Francisco, Calif., ormay be compiled from the source code. The ALIGN-2 program should becompiled for use on a UNIX operating system, including digital UNIXV4.0D. All sequence comparison parameters are set by the ALIGN-2 programand do not vary.

In situations where ALIGN-2 is employed for amino acid sequencecomparisons, the % amino acid sequence identity of a given amino acidsequence A to, with, or against a given amino acid sequence B (which canalternatively be phrased as a given amino acid sequence A that has orcomprises a certain % amino acid sequence identity to, with, or againsta given amino acid sequence B) is calculated as follows:100 times the fraction X/Ywhere X is the number of amino acid residues scored as identical matchesby the sequence alignment program ALIGN-2 in that program's alignment ofA and B, and where Y is the total number of amino acid residues in B. Itwill be appreciated that where the length of amino acid sequence A isnot equal to the length of amino acid sequence B, the % amino acidsequence identity of A to B will not equal the % amino acid sequenceidentity of B to A. Unless specifically stated otherwise, all % aminoacid sequence identity values used herein are obtained as described inthe immediately preceding paragraph using the ALIGN-2 computer program.

The term “pharmaceutical formulation” refers to a preparation which isin such form as to permit the biological activity of an activeingredient contained therein to be effective, and which contains noadditional components which are unacceptably toxic to a subject to whichthe formulation would be administered.

A “pharmaceutically acceptable carrier” refers to an ingredient in apharmaceutical formulation, other than an active ingredient, which isnontoxic to a subject. A pharmaceutically acceptable carrier includes,but is not limited to, a buffer, excipient, stabilizer, or preservative.

The term “Low-density lipoprotein receptor-related protein 5” or “LRP5,”as used herein, refers to any native LRP5 from any vertebrate source,including mammals such as primates (e.g. humans) and rodents (e.g., miceand rats), unless otherwise indicated. The term encompasses“full-length,” unprocessed LRP5 as well as any form of LRP5 that resultsfrom processing in the cell. The term also encompasses naturallyoccurring variants of LRP5, e.g., splice variants or allelic variants.The amino acid sequence of an exemplary human LRP5 is as follows:

(SEQ ID NO: 42) MEAAPPGPPWPLLLLLLLLLALCGCPAPAAASPLLLFANRRDVRLVDAGGVKLESTIVVSGLEDAAAVDFQFSKGAVYWTDVSEEAIKQTYLNQTGAAVQNVVISGLVSPDGLACDWVGKKLYWTDSETNRIEVANLNGTSRKVLFWQDLDQPRAIALDPAHGYMYWTDWGETPRIERAGMDGSTRKIIVDSDIYWPNGLTIDLEEQKLYWADAKLSFIHRANLDGSFRQKVVEGSLTHPFALTLSGDTLYWTDWQTRSIHACNKRTGGKRKEILSALYSPMDIQVLSQERQPFFHTRCEEDNGGCSHLCLLSPSEPFYTCACPTGVQLQDNGRTCKAGAEEVLLLARRTDLRRISLDTPDFTDIVLQVDDIRHAIAIDYDPLEGYVYWTDDEVRAIRRAYLDGSGAQTLVNTEINDPDGIAVDWVARNLYWTDTGTDRIEVTRLNGTSRKILVSEDLDEPRAIALHPVMGLMYWTDWGENPKIECANLDGQERRVLVNASLGWPNGLALDLQEGKLYWGDAKTDKIEVINVDGTKRRTLLEDKLPHIFGFTLLGDFIYWTDWQRRSIERVHKVKASRDVIIDQLPDLMGLKAVNVAKVVGTNPCADRNGGCSHLCFFTPHATRCGCPIGLELLSDMKTCIVPEAFLVFTSRAAIHRISLETNNNDVAIPLTGVKEASALDFDVSNNHIYWTDVSLKTISRAFMNGSSVEHVVEFGLDYPEGMAVDWMGKNLYWADTGTNRIEVARLDGQFRQVLVWRDLDNPRSLALDPTKGYIYWTEWGGKPRIVRAFMDGTNCMTLVDKVGRANDLTIDYADQRLYWTDLDTNMIESSNMLGQERVVIADDLPHPFGLTQYSDYIYWTDWNLHSIERADKTSGRNRTLIQGHLDFVMDILVFHSSRQDGLNDCMHNNGQCGQLCLAIPGGHRCGCASHYTLDPSSRNCSPPTTFLLFSQKSAISRMIPDDQHSPDLILPLHGLRNVKAIDYDPLDKFIYWVDGRQNIKRAKDDGTQPFVLTSLSQGQNPDRQPHDLSIDIYSRTLFWTCEATNTINVHRLSGEAMGVVLRGDRDKPRAIVVNAERGYLYFTNMQDRAAKIERAALDGTEREVLFTTGLIRPVALVVDNTLGKLFWVDADLKRIESCDLSGANRLTLEDANIVQPLGLTILGKHLYWIDRQQQMIERVEKTTGDKRTRIQGRVAHLTGIHAVEEVSLEEFSAHPCARDNGGCSHICIAKGDGTPRCSCPVHLVLLQNLLTCGEPPTCSPDQFACATGEIDCIPGAWRCDGFPECDDQSDEEGCPVCSAAQFPCARGQCVDLRLRCDGEADCQDRSDEADCDAICLPNQFRCASGQCVLIKQQCDSFPDCIDGSDELMCEITKPPSDDSPAHSSAIGPVIGIILSLFVMGGVYFVCQRVVCQRYAGANGPFPHEYVSGTPHVPLNFIAPGGSQHGPFTGIACGKSMMSSVSLMGGRGGVPLYDRNHVTGASSSSSSSTKATLYPPILNPPPSPATDPSLYNMDMFYSSNIPATARPYRPYIIRGMAPPTTPCSTDVCDSDYSASRWKASKYYLDLNSDSDPYPPPPTPHSQYLSAEDSCPPSPATERSY FHLFPPPPSPCTDSS.

As used herein, “treatment” (and grammatical variations thereof such as“treat” or “treating”) refers to clinical intervention in an attempt toalter the natural course of the individual being treated, and can beperformed either for prophylaxis or during the course of clinicalpathology. Desirable effects of treatment include, but are not limitedto, preventing occurrence or recurrence of disease, alleviation ofsymptoms, diminishment of any direct or indirect pathologicalconsequences of the disease, preventing metastasis, decreasing the rateof disease progression, amelioration or palliation of the disease state,and remission or improved prognosis. In some embodiments, antibodies ofthe invention are used to delay development of a disease or to slow theprogression of a disease.

The term “variable region” or “variable domain” refers to the domain ofan antibody heavy or light chain that is involved in binding theantibody to antigen. The variable domains of the heavy chain and lightchain (VH and VL, respectively) of a native antibody generally havesimilar structures, with each domain comprising four conserved frameworkregions (FRs) and three hypervariable regions (HVRs). (See, e.g., Kindtet al. Kuby Immunology, 6^(th) ed., W.H. Freeman and Co., page 91(2007).) A single VH or VL domain may be sufficient to conferantigen-binding specificity. Furthermore, antibodies that bind aparticular antigen may be isolated using a VH or VL domain from anantibody that binds the antigen to screen a library of complementary VLor VH domains, respectively. See, e.g., Portolano et al., J. Immunol.150:880-887 (1993); Clarkson et al., Nature 352:624-628 (1991).

The term “vector,” as used herein, refers to a nucleic acid moleculecapable of propagating another nucleic acid to which it is linked. Theterm includes the vector as a self-replicating nucleic acid structure aswell as the vector incorporated into the genome of a host cell intowhich it has been introduced. Certain vectors are capable of directingthe expression of nucleic acids to which they are operatively linked.Such vectors are referred to herein as “expression vectors.”

II. Compositions and Methods

In one aspect, the invention is based, in part, on the discovery ofantibodies that potentiate Norrin and/or Norrin/Frizzled4 signalling. Incertain embodiments, antibodies that bind to LRP5 are provided.Antibodies of the invention are useful, e.g., for the diagnosis ortreatment of retinopathies including proliferative diabetic retinopathy,CNV, AMD, diabetic and other ischemia-related retinopathies, DME,pathological myopia, von Hippel-Lindau disease, histoplasmosis of theeye, CRVO, BRVO, corneal neovascularization, retinal neovascularization,ROP, FEVR, Coats' disease, Norrie Disease, OPPG(Osteoporosis-Pseudoglioma Syndrome), subconjunctival hemorrhage, andhypertensive retinopathy.

A. Exemplary Anti-LRP5 Antibodies

In one aspect, the invention provides isolated antibodies that bind toLRP5. In certain embodiments, an anti-LRP5 antibody potentiates Norrinactivity and/or Norrin/Fzd4 signaling.

In one aspect, the invention provides an anti-PRO antibody comprising atleast one, two, three, four, five, or six HVRs selected from (a) HVR-H1comprising the amino acid sequence of SEQ ID NO: 28; (b) HVR-H2comprising the amino acid sequence of SEQ ID NO:26 or 27; (c) HVR-H3comprising the amino acid sequence of SEQ ID NO: 23 or 24; (d) HVR-L1comprising the amino acid sequence of SEQ ID NO: 29 or 30; (e) HVR-L2comprising the amino acid sequence of SEQ ID NO: 31 or 32; and (f)HVR-L3 comprising the amino acid sequence of SEQ ID NO: 33.

In one aspect, the invention provides an antibody comprising at leastone, at least two, or all three VH HVR sequences selected from (a)HVR-H1 comprising the amino acid sequence of SEQ ID NO: 28; (b) HVR-H2comprising the amino acid sequence of SEQ ID NO: 26 or 27; and (c)HVR-H3 comprising the amino acid sequence of SEQ ID NO: 23 or 24. In oneembodiment, the antibody comprises HVR-H3 comprising the amino acidsequence of SEQ ID NO: 23 or 24. In another embodiment, the antibodycomprises HVR-H3 comprising the amino acid sequence of SEQ ID NO: 23 or24 and HVR-L3 comprising the amino acid sequence of SEQ ID NO: 33. In afurther embodiment, the antibody comprises HVR-H3 comprising the aminoacid sequence of SEQ ID NO: 23 or 24, HVR-L3 comprising the amino acidsequence of SEQ ID NO: 33, and HVR-H2 comprising the amino acid sequenceof SEQ ID NO: 26 or 27. In a further embodiment, the antibody comprises(a) HVR-H1 comprising the amino acid sequence of SEQ ID NO: 28; (b)HVR-H2 comprising the amino acid sequence of SEQ ID NO: 26 or 27; and(c) HVR-H3 comprising the amino acid sequence of SEQ ID NO: 23 or 24.

In another aspect, the invention provides an antibody comprising atleast one, at least two, or all three VL HVR sequences selected from (a)HVR-L1 comprising the amino acid sequence of SEQ ID NO: 29 or 30; (b)HVR-L2 comprising the amino acid sequence of SEQ ID NO: 31 or 32; and(c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 33. In oneembodiment, the antibody comprises (a) HVR-L1 comprising the amino acidsequence of SEQ ID NO: 29 or 30; (b) HVR-L2 comprising the amino acidsequence of SEQ ID NO: 31 or 32; and (c) HVR-L3 comprising the aminoacid sequence of SEQ ID NO: 33.

In another aspect, an antibody of the invention comprises (a) a VHdomain comprising at least one, at least two, or all three VH HVRsequences selected from (i) HVR-H1 comprising the amino acid sequence ofSEQ ID NO: 28, (ii) HVR-H2 comprising the amino acid sequence of SEQ IDNO: 26 or 27, and (iii) HVR-H3 comprising an amino acid sequenceselected from SEQ ID NO: 23 or 24; and (b) a VL domain comprising atleast one, at least two, or all three VL HVR sequences selected from (i)HVR-L1 comprising the amino acid sequence of SEQ ID NO: 29 or 30, (ii)HVR-L2 comprising the amino acid sequence of SEQ ID NO: 31 or 32, and(c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 33.

In another aspect, the invention provides an antibody comprising (a)HVR-H1 comprising the amino acid sequence of SEQ ID NO: 28; (b) HVR-H2comprising the amino acid sequence of SEQ ID NO: 26 or 27; (c) HVR-H3comprising the amino acid sequence of SEQ ID NO: 23 or 24; (d) HVR-L1comprising the amino acid sequence of SEQ ID NO: 29 or 30; (e) HVR-L2comprising the amino acid sequence of SEQ ID NO: 31 or 32; and (0 HVR-L3comprising an amino acid sequence selected from SEQ ID NO: 33.

In any of the above embodiments, an anti-LRP5 antibody may be humanized.In one embodiment, an anti-LRP5 antibody comprises HVRs as in any of theabove embodiments, and further comprises an acceptor human framework,e.g. a human immunoglobulin framework or a human consensus framework. Inanother embodiment, an anti-LRP5 antibody comprises HVRs as in any ofthe above embodiments, and further comprises a VH or VL comprising an FRsequence, wherein the FR sequences are as follows. For the heavy chain,FR1 comprises the sequence EVQLVESGGGLVQPGGSLRLSCAAS (SEQ ID NO: 34),FR2 comprises the sequence WVRQAPGKGLEWV (SEQ ID NO: 35), FR3 comprisesthe sequence RFTISRDNSKNTLYLQMNSLRAEDTAVYYCAR (SEQ ID NO: 36), FR4comprises the sequence WGQ (SEQ ID NO: 37). For the light chain, FR1comprises the sequence DIQMTQSPSSLSASVGDRVTITC (SEQ ID NO: 38), FR2comprises the sequence WYQQKPGKAPKLLIY (SEQ ID NO: 39), FR3 comprisesthe sequence GVPSRFSGSGSGTDFTLTISSLQPEDFATYYC (SEQ ID NO: 40), FR4comprises the sequence FGQGTKVEIKR (SEQ ID NO: 41).

In another aspect, an anti-LRP5 antibody comprises a heavy chainvariable domain (VH) sequence having at least 90%, 91%, 92%, 93%, 94%,95%, 96%, 97%, 98%, 99%, or 100% sequence identity to the amino acidsequence of any one of SEQ ID NOs: 1-11. In certain embodiments, a VHsequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% identity contains substitutions (e.g., conservative substitutions),insertions, or deletions relative to the reference sequence, but ananti-LRP5 antibody comprising that sequence retains the ability to bindto LRP5. In certain embodiments, a total of 1 to 10 amino acids havebeen substituted, inserted and/or deleted in any one of SEQ ID NOs:1-11. In certain embodiments, substitutions, insertions, or deletionsoccur in regions outside the HVRs (i.e., in the FRs). Optionally, theanti-LRP5 antibody comprises the VH sequence in any one of SEQ ID NOs:1-11, including post-translational modifications of that sequence. In aparticular embodiment, the VH comprises one, two or three HVRs selectedfrom: (a) HVR-H1 comprising the amino acid sequence of SEQ ID NO: 28,(b) HVR-H2 comprising the amino acid sequence of SEQ ID NO: 26 or 27,and (c) HVR-H3 comprising the amino acid sequence of SEQ ID NO: 23 or24.

In another aspect, an anti-LRP5 antibody is provided, wherein theantibody comprises a light chain variable domain (VL) having at least90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequenceidentity to the amino acid sequence of SEQ ID NO: 12-22. In certainembodiments, a VL sequence having at least 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% identity contains substitutions (e.g.,conservative substitutions), insertions, or deletions relative to thereference sequence, but an anti-PRO antibody comprising that sequenceretains the ability to bind to PRO. In certain embodiments, a total of 1to 10 amino acids have been substituted, inserted and/or deleted in SEQID NO: 12-22. In certain embodiments, the substitutions, insertions, ordeletions occur in regions outside the HVRs (i.e., in the FRs).Optionally, the anti-LRP5 antibody comprises the VL sequence in SEQ IDNO: 12-22, including post-translational modifications of that sequence.In a particular embodiment, the VL comprises one, two or three HVRsselected from (a) HVR-L1 comprising the amino acid sequence of SEQ IDNO: 29 or 30; (b) HVR-L2 comprising the amino acid sequence of SEQ IDNO: 31 or 32; and (c) HVR-L3 comprising the amino acid sequence of SEQID NO: 33.

In another aspect, an anti-LRP5 antibody is provided, wherein theantibody comprises a VH as in any of the embodiments provided above, anda VL as in any of the embodiments provided above. In one embodiment, theantibody comprises the VH and VL sequences in any one of SEQ ID NOs:1-11 and SEQ ID NOs: 12-22, respectively, including post-translationalmodifications of those sequences. In some embodiments, the antibodycomprises VH and VL sequences as follows: SEQ ID NO: 1 and SEQ ID NO:12, SEQ ID NO: 2 and SEQ ID NO: 13, SEQ ID NO: 3 and SEQ ID NO: 14, SEQID NO: 4 and SEQ ID NO: 15, SEQ ID NO: 5 and SEQ ID NO: 16, SEQ ID NO: 6and SEQ ID NO: 17, SEQ ID NO: 7 and SEQ ID NO: 18, SEQ ID NO: 8 and SEQID NO: 19, SEQ ID NO: 9 and SEQ ID NO: 20, SEQ ID NO: 10 and SEQ ID NO:21, or SEQ ID NO: 11 and SEQ ID NO: 22.

In a further aspect, the invention provides an antibody that binds tothe same epitope as an anti-LRP5 antibody provided herein. For example,in certain embodiments, an antibody is provided that binds to the sameepitope as an anti-LRP5 antibody comprising a VH sequence of SEQ ID NO:1 and a VL sequence of SEQ ID NO: 12 or comprising a VH sequence of SEQID NO: 5 and a VL sequence of SEQ ID NO: 16.

In a further aspect of the invention, an anti-LRP5 antibody according toany of the above embodiments is a monoclonal antibody, including achimeric, humanized or human antibody. In one embodiment, an anti-LRP5antibody is an antibody fragment, e.g., a Fv, Fab, Fab′, scFv, diabody,or F(ab′)₂ fragment. In another embodiment, the antibody is a fulllength antibody, e.g., an intact IgG1 antibody or other antibody classor isotype as defined herein.

In a further aspect, an anti-LRP5 antibody according to any of the aboveembodiments may incorporate any of the features, singly or incombination, as described in Sections 1-7 below:

1. Antibody Affinity

In certain embodiments, an antibody provided herein has a dissociationconstant (Kd) of ≦1 μM, ≦100 nM, ≦10 nM, ≦1 nM, ≦0.1 nM, ≦0.01 nM, or≦0.001 nM (e.g. 10⁻⁸ M or less, e.g. from 10⁻⁸ M to 10⁻¹³ M, e.g., from10⁻⁹ M to 10⁻¹³ M).

In one embodiment, Kd is measured by a radiolabeled antigen bindingassay (RIA) performed with the Fab version of an antibody of interestand its antigen as described by the following assay. Solution bindingaffinity of Fabs for antigen is measured by equilibrating Fab with aminimal concentration of (¹²⁵I)-labeled antigen in the presence of atitration series of unlabeled antigen, then capturing bound antigen withan anti-Fab antibody-coated plate (see, e.g., Chen et al., J. Mol. Biol.293:865-881(1999)). To establish conditions for the assay, MICROTITER®multi-well plates (Thermo Scientific) are coated overnight with 5 μg/mlof a capturing anti-Fab antibody (Cappel Labs) in 50 mM sodium carbonate(pH 9.6), and subsequently blocked with 2% (w/v) bovine serum albumin inPBS for two to five hours at room temperature (approximately 23° C.). Ina non-adsorbent plate (Nunc #269620), 100 pM or 26 pM [¹²⁵I]-antigen aremixed with serial dilutions of a Fab of interest (e.g., consistent withassessment of the anti-VEGF antibody, Fab-12, in Presta et al., CancerRes. 57:4593-4599 (1997)). The Fab of interest is then incubatedovernight; however, the incubation may continue for a longer period(e.g., about 65 hours) to ensure that equilibrium is reached.Thereafter, the mixtures are transferred to the capture plate forincubation at room temperature (e.g., for one hour). The solution isthen removed and the plate washed eight times with 0.1% polysorbate 20(TWEEN-20®) in PBS. When the plates have dried, 150 μl/well ofscintillant (MICROSCINT-20™; Packard) is added, and the plates arecounted on a TOPCOUNT™ gamma counter (Packard) for ten minutes.Concentrations of each Fab that give less than or equal to 20% ofmaximal binding are chosen for use in competitive binding assays.

According to another embodiment, Kd is measured using surface plasmonresonance assays using a BIACORE®-2000 or a BIACORE®-3000 (BIAcore,Inc., Piscataway, N.J.) at 25° C. with immobilized antigen CM5 chips at˜10 response units (RU). Briefly, carboxymethylated dextran biosensorchips (CM5, BIACORE, Inc.) are activated withN-ethyl-N′-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC) andN-hydroxysuccinimide (NHS) according to the supplier's instructions.Antigen is diluted with 10 mM sodium acetate, pH 4.8, to 5 μg/ml (˜0.2μM) before injection at a flow rate of 5 μl/minute to achieveapproximately 10 response units (RU) of coupled protein. Following theinjection of antigen, 1 M ethanolamine is injected to block unreactedgroups. For kinetics measurements, two-fold serial dilutions of Fab(0.78 nM to 500 nM) are injected in PBS with 0.05% polysorbate 20(TWEEN-20™) surfactant (PBST) at 25° C. at a flow rate of approximately25 μl/min. Association rates (k_(on)) and dissociation rates (k_(off))are calculated using a simple one-to-one Langmuir binding model(BIACORE® Evaluation Software version 3.2) by simultaneously fitting theassociation and dissociation sensorgrams. The equilibrium dissociationconstant (Kd) is calculated as the ratio k_(off)/k_(on). See, e.g., Chenet al., J. Mol. Biol. 293:865-881 (1999). If the on-rate exceeds 10⁶ M⁻¹s⁻¹ by the surface plasmon resonance assay above, then the on-rate canbe determined by using a fluorescent quenching technique that measuresthe increase or decrease in fluorescence emission intensity(excitation=295 nm; emission=340 nm, 16 nm band-pass) at 25° C. of a 20nM anti-antigen antibody (Fab form) in PBS, pH 7.2, in the presence ofincreasing concentrations of antigen as measured in a spectrometer, suchas a stop-flow equipped spectrophometer (Aviv Instruments) or a8000-series SLM-AMINCO™ spectrophotometer (ThermoSpectronic) with astirred cuvette.

2. Antibody Fragments

In certain embodiments, an antibody provided herein is an antibodyfragment. Antibody fragments include, but are not limited to, Fab, Fab′,Fab′-SH, F(ab′)₂, Fv, and scFv fragments, and other fragments describedbelow. For a review of certain antibody fragments, see Hudson et al.Nat. Med. 9:129-134 (2003). For a review of scFv fragments, see, e.g.,Pluckthün, in The Pharmacology of Monoclonal Antibodies, vol. 113,Rosenburg and Moore eds., (Springer-Verlag, New York), pp. 269-315(1994); see also WO 93/16185; and U.S. Pat. Nos. 5,571,894 and5,587,458. For discussion of Fab and F(ab′)₂ fragments comprisingsalvage receptor binding epitope residues and having increased in vivohalf-life, see U.S. Pat. No. 5,869,046.

Diabodies are antibody fragments with two antigen-binding sites that maybe bivalent or bispecific. See, for example, EP 404,097; WO 1993/01161;Hudson et al., Nat. Med. 9:129-134 (2003); and Hollinger et al., Proc.Natl. Acad. Sci. USA 90: 6444-6448 (1993). Triabodies and tetrabodiesare also described in Hudson et al., Nat. Med. 9:129-134 (2003).

Single-domain antibodies are antibody fragments comprising all or aportion of the heavy chain variable domain or all or a portion of thelight chain variable domain of an antibody. In certain embodiments, asingle-domain antibody is a human single-domain antibody (Domantis,Inc., Waltham, Mass.; see, e.g., U.S. Pat. No. 6,248,516 B1).

Antibody fragments can be made by various techniques, including but notlimited to proteolytic digestion of an intact antibody as well asproduction by recombinant host cells (e.g. E. coli or phage), asdescribed herein.

3. Chimeric and Humanized Antibodies

In certain embodiments, an antibody provided herein is a chimericantibody. Certain chimeric antibodies are described, e.g., in U.S. Pat.No. 4,816,567; and Morrison et al., Proc. Natl. Acad. Sci. USA,81:6851-6855 (1984)). In one example, a chimeric antibody comprises anon-human variable region (e.g., a variable region derived from a mouse,rat, hamster, rabbit, or non-human primate, such as a monkey) and ahuman constant region. In a further example, a chimeric antibody is a“class switched” antibody in which the class or subclass has beenchanged from that of the parent antibody. Chimeric antibodies includeantigen-binding fragments thereof.

In certain embodiments, a chimeric antibody is a humanized antibody.Typically, a non-human antibody is humanized to reduce immunogenicity tohumans, while retaining the specificity and affinity of the parentalnon-human antibody. Generally, a humanized antibody comprises one ormore variable domains in which HVRs, e.g., CDRs, (or portions thereof)are derived from a non-human antibody, and FRs (or portions thereof) arederived from human antibody sequences. A humanized antibody optionallywill also comprise at least a portion of a human constant region. Insome embodiments, some FR residues in a humanized antibody aresubstituted with corresponding residues from a non-human antibody (e.g.,the antibody from which the HVR residues are derived), e.g., to restoreor improve antibody specificity or affinity.

Humanized antibodies and methods of making them are reviewed, e.g., inAlmagro and Fransson, Front. Biosci. 13:1619-1633 (2008), and arefurther described, e.g., in Riechmann et al., Nature 332:323-329 (1988);Queen et al., Proc. Nat'l Acad. Sci. USA 86:10029-10033 (1989); U.S.Pat. Nos. 5,821,337, 7,527,791, 6,982,321, and 7,087,409; Kashmiri etal., Methods 36:25-34 (2005) (describing SDR (a-CDR) grafting); Padlan,Mol. Immunol. 28:489-498 (1991) (describing “resurfacing”); Dall'Acquaet al., Methods 36:43-60 (2005) (describing “FR shuffling”); and Osbournet al., Methods 36:61-68 (2005) and Klimka et al., Br. J. Cancer,83:252-260 (2000) (describing the “guided selection” approach to FRshuffling).

Human framework regions that may be used for humanization include butare not limited to: framework regions selected using the “best-fit”method (see, e.g., Sims et al. J. Immunol. 151:2296 (1993)); frameworkregions derived from the consensus sequence of human antibodies of aparticular subgroup of light or heavy chain variable regions (see, e.g.,Carter et al. Proc. Natl. Acad. Sci. USA, 89:4285 (1992); and Presta etal. J. Immunol., 151:2623 (1993)); human mature (somatically mutated)framework regions or human germline framework regions (see, e.g.,Almagro and Fransson, Front. Biosci. 13:1619-1633 (2008)); and frameworkregions derived from screening FR libraries (see, e.g., Baca et al., J.Biol. Chem. 272:10678-10684 (1997) and Rosok et al., J. Biol. Chem.271:22611-22618 (1996)).

4. Human Antibodies

In certain embodiments, an antibody provided herein is a human antibody.Human antibodies can be produced using various techniques known in theart. Human antibodies are described generally in van Dijk and van deWinkel, Curr. Opin. Pharmacol. 5: 368-74 (2001) and Lonberg, Curr. Opin.Immunol. 20:450-459 (2008).

Human antibodies may be prepared by administering an immunogen to atransgenic animal that has been modified to produce intact humanantibodies or intact antibodies with human variable regions in responseto antigenic challenge. Such animals typically contain all or a portionof the human immunoglobulin loci, which replace the endogenousimmunoglobulin loci, or which are present extrachromosomally orintegrated randomly into the animal's chromosomes. In such transgenicmice, the endogenous immunoglobulin loci have generally beeninactivated. For review of methods for obtaining human antibodies fromtransgenic animals, see Lonberg, Nat. Biotech. 23:1117-1125 (2005). Seealso, e.g., U.S. Pat. Nos. 6,075,181 and 6,150,584 describing XENOMOUSE™technology; U.S. Pat. No. 5,770,429 describing HUMAB® technology; U.S.Pat. No. 7,041,870 describing K-M MOUSE® technology, and U.S. PatentApplication Publication No. US 2007/0061900, describing VELOCIMOUSE®technology). Human variable regions from intact antibodies generated bysuch animals may be further modified, e.g., by combining with adifferent human constant region.

Human antibodies can also be made by hybridoma-based methods. Humanmyeloma and mouse-human heteromyeloma cell lines for the production ofhuman monoclonal antibodies have been described. (See, e.g., Kozbor J.Immunol., 133: 3001 (1984); Brodeur et al., Monoclonal AntibodyProduction Techniques and Applications, pp. 51-63 (Marcel Dekker, Inc.,New York, 1987); and Boerner et al., J. Immunol., 147: 86 (1991).) Humanantibodies generated via human B-cell hybridoma technology are alsodescribed in Li et al., Proc. Natl. Acad. Sci. USA, 103:3557-3562(2006). Additional methods include those described, for example, in U.S.Pat. No. 7,189,826 (describing production of monoclonal human IgMantibodies from hybridoma cell lines) and Ni, Xiandai Mianyixue,26(4):265-268 (2006) (describing human-human hybridomas). Humanhybridoma technology (Trioma technology) is also described in Vollmersand Brandlein, Histology and Histopathology, 20(3):927-937 (2005) andVollmers and Brandlein, Methods and Findings in Experimental andClinical Pharmacology, 27(3):185-91 (2005).

Human antibodies may also be generated by isolating Fv clone variabledomain sequences selected from human-derived phage display libraries.Such variable domain sequences may then be combined with a desired humanconstant domain. Techniques for selecting human antibodies from antibodylibraries are described below.

5. Library-Derived Antibodies

Antibodies of the invention may be isolated by screening combinatoriallibraries for antibodies with the desired activity or activities. Forexample, a variety of methods are known in the art for generating phagedisplay libraries and screening such libraries for antibodies possessingthe desired binding characteristics. Such methods are reviewed, e.g., inHoogenboom et al. in Methods in Molecular Biology 178:1-37 (O'Brien etal., ed., Human Press, Totowa, N.J., 2001) and further described, e.g.,in the McCafferty et al., Nature 348:552-554; Clackson et al., Nature352: 624-628 (1991); Marks et al., J. Mol. Biol. 222: 581-597 (1992);Marks and Bradbury, in Methods in Molecular Biology 248:161-175 (Lo,ed., Human Press, Totowa, N.J., 2003); Sidhu et al., J. Mol. Biol.338(2): 299-310 (2004); Lee et al., J. Mol. Biol. 340(5): 1073-1093(2004); Fellouse, Proc. Natl. Acad. Sci. USA 101(34): 12467-12472(2004); and Lee et al., J. Immunol. Methods 284(1-2): 119-132(2004).

In certain phage display methods, repertoires of VH and VL genes areseparately cloned by polymerase chain reaction (PCR) and recombinedrandomly in phage libraries, which can then be screened forantigen-binding phage as described in Winter et al., Ann. Rev. Immunol.,12: 433-455 (1994). Phage typically display antibody fragments, eitheras single-chain Fv (scFv) fragments or as Fab fragments. Libraries fromimmunized sources provide high-affinity antibodies to the immunogenwithout the requirement of constructing hybridomas. Alternatively, thenaive repertoire can be cloned (e.g., from human) to provide a singlesource of antibodies to a wide range of non-self and also self antigenswithout any immunization as described by Griffiths et al., EMBO J, 12:725-734 (1993). Finally, naive libraries can also be made syntheticallyby cloning unrearranged V-gene segments from stem cells, and using PCRprimers containing random sequence to encode the highly variable CDR3regions and to accomplish rearrangement in vitro, as described byHoogenboom and Winter, J. Mol. Biol., 227: 381-388 (1992). Patentpublications describing human antibody phage libraries include, forexample: U.S. Pat. No. 5,750,373, and US Patent Publication Nos.2005/0079574, 2005/0119455, 2005/0266000, 2007/0117126, 2007/0160598,2007/0237764, 2007/0292936, and 2009/0002360.

Antibodies or antibody fragments isolated from human antibody librariesare considered human antibodies or human antibody fragments herein.

6. Multispecific Antibodies

In certain embodiments, an antibody provided herein is a multispecificantibody, e.g. a bispecific antibody. Multispecific antibodies aremonoclonal antibodies that have binding specificities for at least twodifferent sites. In certain embodiments, one of the bindingspecificities is for LRP5 and the other is for any other antigen. Incertain embodiments, the other binding specificity if for vascularendothelial growth factor (VEGF). In certain embodiments, bispecificantibodies may bind to two different epitopes of LRP5. Bispecificantibodies may also be used to localize cytotoxic agents to cells whichexpress LRP5. Bispecific antibodies can be prepared as full lengthantibodies or antibody fragments.

Techniques for making multispecific antibodies include, but are notlimited to, recombinant co-expression of two immunoglobulin heavychain-light chain pairs having different specificities (see Milstein andCuello, Nature 305: 537 (1983)), WO 93/08829, and Traunecker et al.,EMBO J. 10: 3655 (1991)), and “knob-in-hole” engineering (see, e.g.,U.S. Pat. No. 5,731,168). Multi-specific antibodies may also be made byengineering electrostatic steering effects for making antibodyFc-heterodimeric molecules (WO 2009/089004A1); cross-linking two or moreantibodies or fragments (see, e.g., U.S. Pat. No. 4,676,980, and Brennanet al., Science, 229: 81 (1985)); using leucine zippers to producebi-specific antibodies (see, e.g., Kostelny et al., J. Immunol.,148(5):1547-1553 (1992)); using “diabody” technology for makingbispecific antibody fragments (see, e.g., Hollinger et al., Proc. Natl.Acad. Sci. USA, 90:6444-6448 (1993)); and using single-chain Fv (sFv)dimers (see, e.g. Gruber et al., J. Immunol., 152:5368 (1994)); andpreparing trispecific antibodies as described, e.g., in Tutt et al. J.Immunol. 147: 60 (1991).

Engineered antibodies with three or more functional antigen bindingsites, including “Octopus antibodies,” are also included herein (see,e.g. US 2006/0025576A1).

The antibody or fragment herein also includes a “Dual Acting FAb” or“DAF” comprising an antigen binding site that binds to LRP5 as well asanother, different antigen (see, US 2008/0069820, for example).

7. Antibody Variants

In certain embodiments, amino acid sequence variants of the antibodiesprovided herein are contemplated. For example, it may be desirable toimprove the binding affinity and/or other biological properties of theantibody. Amino acid sequence variants of an antibody may be prepared byintroducing appropriate modifications into the nucleotide sequenceencoding the antibody, or by peptide synthesis. Such modificationsinclude, for example, deletions from, and/or insertions into and/orsubstitutions of residues within the amino acid sequences of theantibody. Any combination of deletion, insertion, and substitution canbe made to arrive at the final construct, provided that the finalconstruct possesses the desired characteristics, e.g., antigen-binding.

a) Substitution, Insertion, and Deletion Variants

In certain embodiments, antibody variants having one or more amino acidsubstitutions are provided. Sites of interest for substitutionalmutagenesis include the HVRs and FRs. Conservative substitutions areshown in Table 1 under the heading of “conservative substitutions.” Moresubstantial changes are provided in Table 1 under the heading of“exemplary substitutions,” and as further described below in referenceto amino acid side chain classes. Amino acid substitutions may beintroduced into an antibody of interest and the products screened for adesired activity, e.g., retained/improved antigen binding, decreasedimmunogenicity, or improved ADCC or CDC.

TABLE 1 Original Exemplary Preferred Residue Substitutions SubstitutionsAla (A) Val; Leu; Ile Val Arg (R) Lys; Gln; Asn Lys Asn (N) Gln; His;Asp, Lys; Arg Gln Asp (D) Glu; Asn Glu Cys (C) Ser; Ala Ser Gln (Q) Asn;Glu Asn Glu (E) Asp; Gln Asp Gly (G) Ala Ala His (H) Asn; Gln; Lys; ArgArg Ile (I) Leu; Val; Met; Ala; Phe; Norleucine Leu Leu (L) Norleucine;Ile; Val; Met; Ala; Phe Ile Lys (K) Arg; Gln; Asn Arg Met (M) Leu; Phe;Ile Leu Phe (F) Trp; Leu; Val; Ile; Ala; Tyr Tyr Pro (P) Ala Ala Ser (S)Thr Thr Thr (T) Val; Ser Ser Trp (W) Tyr; Phe Tyr Tyr (Y) Trp; Phe; Thr;Ser Phe Val (V) Ile; Leu; Met; Phe; Ala; Norleucine Leu

Amino acids may be grouped according to common side-chain properties:

(1) hydrophobic: Norleucine, Met, Ala, Val, Leu, Ile;

(2) neutral hydrophilic: Cys, Ser, Thr, Asn, Gln;

(3) acidic: Asp, Glu;

(4) basic: His, Lys, Arg;

(5) residues that influence chain orientation: Gly, Pro;

(6) aromatic: Trp, Tyr, Phe.

Non-conservative substitutions will entail exchanging a member of one ofthese classes for another class.

One type of substitutional variant involves substituting one or morehypervariable region residues of a parent antibody (e.g. a humanized orhuman antibody). Generally, the resulting variant(s) selected forfurther study will have modifications (e.g., improvements) in certainbiological properties (e.g., increased affinity, reduced immunogenicity)relative to the parent antibody and/or will have substantially retainedcertain biological properties of the parent antibody. An exemplarysubstitutional variant is an affinity matured antibody, which may beconveniently generated, e.g., using phage display-based affinitymaturation techniques such as those described herein. Briefly, one ormore HVR residues are mutated and the variant antibodies displayed onphage and screened for a particular biological activity (e.g. bindingaffinity).

Alterations (e.g., substitutions) may be made in HVRs, e.g., to improveantibody affinity. Such alterations may be made in HVR “hotspots,” i.e.,residues encoded by codons that undergo mutation at high frequencyduring the somatic maturation process (see, e.g., Chowdhury, MethodsMol. Biol. 207:179-196 (2008)), and/or SDRs (a-CDRs), with the resultingvariant VH or VL being tested for binding affinity. Affinity maturationby constructing and reselecting from secondary libraries has beendescribed, e.g., in Hoogenboom et al. in Methods in Molecular Biology178:1-37 (O'Brien et al., ed., Human Press, Totowa, N.J., (2001).) Insome embodiments of affinity maturation, diversity is introduced intothe variable genes chosen for maturation by any of a variety of methods(e.g., error-prone PCR, chain shuffling, or oligonucleotide-directedmutagenesis). A secondary library is then created. The library is thenscreened to identify any antibody variants with the desired affinity.Another method to introduce diversity involves HVR-directed approaches,in which several HVR residues (e.g., 4-6 residues at a time) arerandomized. HVR residues involved in antigen binding may be specificallyidentified, e.g., using alanine scanning mutagenesis or modeling. CDR-H3and CDR-L3 in particular are often targeted.

In certain embodiments, substitutions, insertions, or deletions mayoccur within one or more HVRs so long as such alterations do notsubstantially reduce the ability of the antibody to bind antigen. Forexample, conservative alterations (e.g., conservative substitutions asprovided herein) that do not substantially reduce binding affinity maybe made in HVRs. Such alterations may be outside of HVR “hotspots” orSDRs. In certain embodiments of the variant VH and VL sequences providedabove, each HVR either is unaltered, or contains no more than one, twoor three amino acid substitutions.

A useful method for identification of residues or regions of an antibodythat may be targeted for mutagenesis is called “alanine scanningmutagenesis” as described by Cunningham and Wells (1989) Science,244:1081-1085. In this method, a residue or group of target residues(e.g., charged residues such as arg, asp, his, lys, and glu) areidentified and replaced by a neutral or negatively charged amino acid(e.g., alanine or polyalanine) to determine whether the interaction ofthe antibody with antigen is affected. Further substitutions may beintroduced at the amino acid locations demonstrating functionalsensitivity to the initial substitutions. Alternatively, oradditionally, a crystal structure of an antigen-antibody complex toidentify contact points between the antibody and antigen. Such contactresidues and neighboring residues may be targeted or eliminated ascandidates for substitution. Variants may be screened to determinewhether they contain the desired properties.

Amino acid sequence insertions include amino- and/or carboxyl-terminalfusions ranging in length from one residue to polypeptides containing ahundred or more residues, as well as intrasequence insertions of singleor multiple amino acid residues. Examples of terminal insertions includean antibody with an N-terminal methionyl residue. Other insertionalvariants of the antibody molecule include the fusion to the N- orC-terminus of the antibody to an enzyme (e.g. for ADEPT) or apolypeptide which increases the serum half-life of the antibody.

b) Glycosylation Variants

In certain embodiments, an antibody provided herein is altered toincrease or decrease the extent to which the antibody is glycosylated.Addition or deletion of glycosylation sites to an antibody may beconveniently accomplished by altering the amino acid sequence such thatone or more glycosylation sites is created or removed.

Where the antibody comprises an Fc region, the carbohydrate attachedthereto may be altered. Native antibodies produced by mammalian cellstypically comprise a branched, biantennary oligosaccharide that isgenerally attached by an N-linkage to Asn297 of the CH2 domain of the Fcregion. See, e.g., Wright et al. TIBTECH 15:26-32 (1997). Theoligosaccharide may include various carbohydrates, e.g., mannose,N-acetyl glucosamine (GlcNAc), galactose, and sialic acid, as well as afucose attached to a GlcNAc in the “stem” of the biantennaryoligosaccharide structure. In some embodiments, modifications of theoligosaccharide in an antibody of the invention may be made in order tocreate antibody variants with certain improved properties.

In one embodiment, antibody variants are provided having a carbohydratestructure that lacks fucose attached (directly or indirectly) to an Fcregion. For example, the amount of fucose in such antibody may be from1% to 80%, from 1% to 65%, from 5% to 65% or from 20% to 40%. The amountof fucose is determined by calculating the average amount of fucosewithin the sugar chain at Asn297, relative to the sum of allglycostructures attached to Asn 297 (e. g. complex, hybrid and highmannose structures) as measured by MALDI-TOF mass spectrometry, asdescribed in WO 2008/077546, for example. Asn297 refers to theasparagine residue located at about position 297 in the Fc region (Eunumbering of Fc region residues); however, Asn297 may also be locatedabout ±3 amino acids upstream or downstream of position 297, i.e.,between positions 294 and 300, due to minor sequence variations inantibodies. Such fucosylation variants may have improved ADCC function.See, e.g., US Patent Publication Nos. US 2003/0157108 (Presta, L.); US2004/0093621 (Kyowa Hakko Kogyo Co., Ltd). Examples of publicationsrelated to “defucosylated” or “fucose-deficient” antibody variantsinclude: US 2003/0157108; WO 2000/61739; WO 2001/29246; US 2003/0115614;US 2002/0164328; US 2004/0093621; US 2004/0132140; US 2004/0110704; US2004/0110282; US 2004/0109865; WO 2003/085119; WO 2003/084570; WO2005/035586; WO 2005/035778; WO2005/053742; WO2002/031140; Okazaki etal. J. Mol. Biol. 336:1239-1249 (2004); Yamane-Ohnuki et al. Biotech.Bioeng. 87: 614 (2004). Examples of cell lines capable of producingdefucosylated antibodies include Lec13 CHO cells deficient in proteinfucosylation (Ripka et al. Arch. Biochem. Biophys. 249:533-545 (1986);US Pat Appl No US 2003/0157108 A1, Presta, L; and WO 2004/056312 A1,Adams et al., especially at Example 11), and knockout cell lines, suchas alpha-1,6-fucosyltransferase gene, FUT8, knockout CHO cells (see,e.g., Yamane-Ohnuki et al. Biotech. Bioeng. 87: 614 (2004); Kanda, Y. etal., Biotechnol. Bioeng., 94(4):680-688 (2006); and WO2003/085107).

Antibodies variants are further provided with bisected oligosaccharides,e.g., in which a biantennary oligosaccharide attached to the Fc regionof the antibody is bisected by GlcNAc. Such antibody variants may havereduced fucosylation and/or improved ADCC function. Examples of suchantibody variants are described, e.g., in WO 2003/011878 (Jean-Mairet etal.); U.S. Pat. No. 6,602,684 (Umana et al.); and US 2005/0123546 (Umanaet al.). Antibody variants with at least one galactose residue in theoligosaccharide attached to the Fc region are also provided. Suchantibody variants may have improved CDC function. Such antibody variantsare described, e.g., in WO 1997/30087 (Patel et al.); WO 1998/58964(Raju, S.); and WO 1999/22764 (Raju, S.).

c) Fc Region Variants

In certain embodiments, one or more amino acid modifications may beintroduced into the Fc region of an antibody provided herein, therebygenerating an Fc region variant. The Fc region variant may comprise ahuman Fc region sequence (e.g., a human IgG1, IgG2, IgG3 or IgG4 Fcregion) comprising an amino acid modification (e.g. a substitution) atone or more amino acid positions.

In certain embodiments, the invention contemplates an antibody variantthat possesses some but not all effector functions, which make it adesirable candidate for applications in which the half life of theantibody in vivo is important yet certain effector functions (such ascomplement and ADCC) are unnecessary or deleterious. In vitro and/or invivo cytotoxicity assays can be conducted to confirm thereduction/depletion of CDC and/or ADCC activities. For example, Fcreceptor (FcR) binding assays can be conducted to ensure that theantibody lacks FcγR binding (hence likely lacking ADCC activity), butretains FcRn binding ability. The primary cells for mediating ADCC, NKcells, express Fc(RIII only, whereas monocytes express Fc(RI, Fc(RII andFc(RIII. FcR expression on hematopoietic cells is summarized in Table 3on page 464 of Ravetch and Kinet, Annu. Rev. Immunol. 9:457-492 (1991).Non-limiting examples of in vitro assays to assess ADCC activity of amolecule of interest is described in U.S. Pat. No. 5,500,362 (see, e.g.Hellstrom, I. et al. Proc. Nat'l Acad. Sci. USA 83:7059-7063 (1986)) andHellstrom, I et al., Proc. Nat'l Acad. Sci. USA 82:1499-1502 (1985);U.S. Pat. No. 5,821,337 (see Bruggemann, M. et al., J. Exp. Med.166:1351-1361 (1987)). Alternatively, non-radioactive assays methods maybe employed (see, for example, ACTI™ non-radioactive cytotoxicity assayfor flow cytometry (CellTechnology, Inc. Mountain View, Calif.; andCytoTox 96® non-radioactive cytotoxicity assay (Promega, Madison, Wis.).Useful effector cells for such assays include peripheral bloodmononuclear cells (PBMC) and Natural Killer (NK) cells. Alternatively,or additionally, ADCC activity of the molecule of interest may beassessed in vivo, e.g., in a animal model such as that disclosed inClynes et al. Proc. Nat'l Acad. Sci. USA 95:652-656 (1998). C1q bindingassays may also be carried out to confirm that the antibody is unable tobind C1q and hence lacks CDC activity. See, e.g., C1q and C3c bindingELISA in WO 2006/029879 and WO 2005/100402. To assess complementactivation, a CDC assay may be performed (see, for example,Gazzano-Santoro et al., J. Immunol. Methods 202:163 (1996); Cragg, M. S.et al., Blood 101:1045-1052 (2003); and Cragg, M. S. and M. J. Glennie,Blood 103:2738-2743 (2004)). FcRn binding and in vivo clearance/halflife determinations can also be performed using methods known in the art(see, e.g., Petkova, S. B. et al., Int'l. Immunol. 18(12):1759-1769(2006)).

Antibodies with reduced effector function include those withsubstitution of one or more of Fc region residues 238, 265, 269, 270,297, 327 and 329 (U.S. Pat. No. 6,737,056). Such Fc mutants include Fcmutants with substitutions at two or more of amino acid positions 265,269, 270, 297 and 327, including the so-called “DANA” Fc mutant withsubstitution of residues 265 and 297 to alanine (U.S. Pat. No.7,332,581).

Certain antibody variants with improved or diminished binding to FcRsare described. (See, e.g., U.S. Pat. No. 6,737,056; WO 2004/056312, andShields et al., J. Biol. Chem. 9(2): 6591-6604 (2001).)

In certain embodiments, an antibody variant comprises an Fc region withone or more amino acid substitutions which improve ADCC, e.g.,substitutions at positions 298, 333, and/or 334 of the Fc region (EUnumbering of residues).

In some embodiments, alterations are made in the Fc region that resultin altered (i.e., either improved or diminished) C1q binding and/orComplement Dependent Cytotoxicity (CDC), e.g., as described in U.S. Pat.No. 6,194,551, WO 99/51642, and Idusogie et al. J. Immunol. 164:4178-4184 (2000).

Antibodies with increased half lives and improved binding to theneonatal Fc receptor (FcRn), which is responsible for the transfer ofmaternal IgGs to the fetus (Guyer et al., J. Immunol. 117:587 (1976) andKim et al., J. Immunol. 24:249 (1994)), are described inUS2005/0014934A1 (Hinton et al.). Those antibodies comprise an Fc regionwith one or more substitutions therein which improve binding of the Fcregion to FcRn. Such Fc variants include those with substitutions at oneor more of Fc region residues: 238, 256, 265, 272, 286, 303, 305, 307,311, 312, 317, 340, 356, 360, 362, 376, 378, 380, 382, 413, 424 or 434,e.g., substitution of Fc region residue 434 (U.S. Pat. No. 7,371,826).

See also Duncan & Winter, Nature 322:738-40 (1988); U.S. Pat. No.5,648,260; U.S. Pat. No. 5,624,821; and WO 94/29351 concerning otherexamples of Fc region variants.

d) Cysteine Engineered Antibody Variants

In certain embodiments, it may be desirable to create cysteineengineered antibodies, e.g., “thioMAbs,” in which one or more residuesof an antibody are substituted with cysteine residues. In particularembodiments, the substituted residues occur at accessible sites of theantibody. By substituting those residues with cysteine, reactive thiolgroups are thereby positioned at accessible sites of the antibody andmay be used to conjugate the antibody to other moieties, such as drugmoieties or linker-drug moieties, to create an immunoconjugate, asdescribed further herein. In certain embodiments, any one or more of thefollowing residues may be substituted with cysteine: V205 (Kabatnumbering) of the light chain; A118 (EU numbering) of the heavy chain;and S400 (EU numbering) of the heavy chain Fc region. Cysteineengineered antibodies may be generated as described, e.g., in U.S. Pat.No. 7,521,541.

e) Antibody Derivatives

In certain embodiments, an antibody provided herein may be furthermodified to contain additional nonproteinaceous moieties that are knownin the art and readily available. The moieties suitable forderivatization of the antibody include but are not limited to watersoluble polymers. Non-limiting examples of water soluble polymersinclude, but are not limited to, polyethylene glycol (PEG), copolymersof ethylene glycol/propylene glycol, carboxymethylcellulose, dextran,polyvinyl alcohol, polyvinyl pyrrolidone, poly-1, 3-dioxolane,poly-1,3,6-trioxane, ethylene/maleic anhydride copolymer, polyaminoacids(either homopolymers or random copolymers), and dextran or poly(n-vinylpyrrolidone)polyethylene glycol, propropylene glycol homopolymers,prolypropylene oxide/ethylene oxide co-polymers, polyoxyethylatedpolyols (e.g., glycerol), polyvinyl alcohol, and mixtures thereof.Polyethylene glycol propionaldehyde may have advantages in manufacturingdue to its stability in water. The polymer may be of any molecularweight, and may be branched or unbranched. The number of polymersattached to the antibody may vary, and if more than one polymer areattached, they can be the same or different molecules. In general, thenumber and/or type of polymers used for derivatization can be determinedbased on considerations including, but not limited to, the particularproperties or functions of the antibody to be improved, whether theantibody derivative will be used in a therapy under defined conditions,etc.

In another embodiment, conjugates of an antibody and nonproteinaceousmoiety that may be selectively heated by exposure to radiation areprovided. In one embodiment, the nonproteinaceous moiety is a carbonnanotube (Kam et al., Proc. Natl. Acad. Sci. USA 102: 11600-11605(2005)). The radiation may be of any wavelength, and includes, but isnot limited to, wavelengths that do not harm ordinary cells, but whichheat the nonproteinaceous moiety to a temperature at which cellsproximal to the antibody-nonproteinaceous moiety are killed.

B. Recombinant Methods and Compositions

Antibodies may be produced using recombinant methods and compositions,e.g., as described in U.S. Pat. No. 4,816,567. In one embodiment,isolated nucleic acid encoding an anti-LRP5 antibody described herein isprovided. Such nucleic acid may encode an amino acid sequence comprisingthe VL and/or an amino acid sequence comprising the VH of the antibody(e.g., the light and/or heavy chains of the antibody). In a furtherembodiment, one or more vectors (e.g., expression vectors) comprisingsuch nucleic acid are provided. In a further embodiment, a host cellcomprising such nucleic acid is provided. In one such embodiment, a hostcell comprises (e.g., has been transformed with): (1) a vectorcomprising a nucleic acid that encodes an amino acid sequence comprisingthe VL of the antibody and an amino acid sequence comprising the VH ofthe antibody, or (2) a first vector comprising a nucleic acid thatencodes an amino acid sequence comprising the VL of the antibody and asecond vector comprising a nucleic acid that encodes an amino acidsequence comprising the VH of the antibody. In one embodiment, the hostcell is eukaryotic, e.g. a Chinese Hamster Ovary (CHO) cell or lymphoidcell (e.g., Y0, NS0, Sp20 cell). In one embodiment, a method of makingan anti-LRP5 antibody is provided, wherein the method comprisesculturing a host cell comprising a nucleic acid encoding the antibody,as provided above, under conditions suitable for expression of theantibody, and optionally recovering the antibody from the host cell (orhost cell culture medium).

For recombinant production of an anti-LRP5 antibody, nucleic acidencoding an antibody, e.g., as described above, is isolated and insertedinto one or more vectors for further cloning and/or expression in a hostcell. Such nucleic acid may be readily isolated and sequenced usingconventional procedures (e.g., by using oligonucleotide probes that arecapable of binding specifically to genes encoding the heavy and lightchains of the antibody).

Suitable host cells for cloning or expression of antibody-encodingvectors include prokaryotic or eukaryotic cells described herein. Forexample, antibodies may be produced in bacteria, in particular whenglycosylation and Fc effector function are not needed. For expression ofantibody fragments and polypeptides in bacteria, see, e.g., U.S. Pat.Nos. 5,648,237, 5,789,199, and 5,840,523. (See also Charlton, Methods inMolecular Biology, Vol. 248 (B. K. C. Lo, ed., Humana Press, Totowa,N.J., 2003), pp. 245-254, describing expression of antibody fragments inE. coli.) After expression, the antibody may be isolated from thebacterial cell paste in a soluble fraction and can be further purified.

In addition to prokaryotes, eukaryotic microbes such as filamentousfungi or yeast are suitable cloning or expression hosts forantibody-encoding vectors, including fungi and yeast strains whoseglycosylation pathways have been “humanized,” resulting in theproduction of an antibody with a partially or fully human glycosylationpattern. See Gerngross, Nat. Biotech. 22:1409-1414 (2004), and Li etal., Nat. Biotech. 24:210-215 (2006).

Suitable host cells for the expression of glycosylated antibody are alsoderived from multicellular organisms (invertebrates and vertebrates).Examples of invertebrate cells include plant and insect cells. Numerousbaculoviral strains have been identified which may be used inconjunction with insect cells, particularly for transfection ofSpodoptera frugiperda cells.

Plant cell cultures can also be utilized as hosts. See, e.g., U.S. Pat.Nos. 5,959,177, 6,040,498, 6,420,548, 7,125,978, and 6,417,429(describing PLANTIBODIES™ technology for producing antibodies intransgenic plants).

Vertebrate cells may also be used as hosts. For example, mammalian celllines that are adapted to grow in suspension may be useful. Otherexamples of useful mammalian host cell lines are monkey kidney CV1 linetransformed by SV40 (COS-7); human embryonic kidney line (293 or 293cells as described, e.g., in Graham et al., J. Gen Virol. 36:59 (1977));baby hamster kidney cells (BHK); mouse sertoli cells (TM4 cells asdescribed, e.g., in Mather, Biol. Reprod. 23:243-251 (1980)); monkeykidney cells (CV1); African green monkey kidney cells (VERO-76); humancervical carcinoma cells (HELA); canine kidney cells (MDCK; buffalo ratliver cells (BRL 3A); human lung cells (W138); human liver cells (HepG2); mouse mammary tumor (MMT 060562); TRI cells, as described, e.g., inMather et al., Annals N.Y. Acad. Sci. 383:44-68 (1982); MRC 5 cells; andFS4 cells. Other useful mammalian host cell lines include Chinesehamster ovary (CHO) cells, including DHFR⁻ CHO cells (Urlaub et al.,Proc. Natl. Acad. Sci. USA 77:4216 (1980)); and myeloma cell lines suchas Y0, NS0 and Sp2/0. For a review of certain mammalian host cell linessuitable for antibody production, see, e.g., Yazaki and Wu, Methods inMolecular Biology, Vol. 248 (B. K. C. Lo, ed., Humana Press, Totowa,N.J.), pp. 255-268 (2003).

C. Assays

Anti-LRP5 antibodies provided herein may be identified, screened for, orcharacterized for their physical/chemical properties and/or biologicalactivities by various assays known in the art.

1. Binding Assays and Other Assays

In one aspect, an antibody of the invention is tested for its antigenbinding activity, e.g., by known methods such as ELISA, Western blot,etc.

In another aspect, competition assays may be used to identify anantibody that competes with YW629.42 or YW629.51 for binding to LRP5. Incertain embodiments, such a competing antibody binds to the same epitope(e.g., a linear or a conformational epitope) that is bound by YW629.42or YW629.51. Detailed exemplary methods for mapping an epitope to whichan antibody binds are provided in Morris (1996) “Epitope MappingProtocols,” in Methods in Molecular Biology vol. 66 (Humana Press,Totowa, N.J.).

In an exemplary competition assay, immobilized LRP5 is incubated in asolution comprising a first labeled antibody that binds to LRP5 (e.g.,YW629.42 or YW629.51) and a second unlabeled antibody that is beingtested for its ability to compete with the first antibody for binding toLRP5. The second antibody may be present in a hybridoma supernatant. Asa control, immobilized LRP5 is incubated in a solution comprising thefirst labeled antibody but not the second unlabeled antibody. Afterincubation under conditions permissive for binding of the first antibodyto LRP5, excess unbound antibody is removed, and the amount of labelassociated with immobilized LRP5 is measured. If the amount of labelassociated with immobilized LRP5 is substantially reduced in the testsample relative to the control sample, then that indicates that thesecond antibody is competing with the first antibody for binding toLRP5. See Harlow and Lane (1988) Antibodies: A Laboratory Manual ch. 14(Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y.).

2. Activity Assays

In one aspect, assays are provided for identifying anti-LRP5 antibodiesthereof having a biological activity. Biological activity may include,e.g., binding to LRP5, potentiation of Norrin activity, or potentiationof Norrin/Fzd4 signaling. Antibodies having such biological activity invivo and/or in vitro are also provided.

In certain embodiments, an antibody of the invention is tested for suchbiological activity. In an exemplary Wnt/Norrin activation assay, LRP5and Fzd4 protein, or relevant variants (ie. Fzd4_(M157V)) aretransiently expressed with Topflash luciferase reporter plasmids in 293Tcells. Cells expressing these proteins are exposed to Norrin or Wntligands and, following an incubation for 16 hours at 37° C., the levelof activation is ascertained by measuring the amount of luminescencefrom luciferase. If the amount of luminescence is substantiallyincreased by ligand addition in the presence of LRP5 antibody then thatindicates that the antibody potentiates Fzd4/Norrin signaling. Whenusing Fzd4_(M157V), which has diminished signaling in the presence ofNorrin, the increase in luminescence in the presence of LRP5 antibody isconsidered to rescue the defect in Fzd4 signaling.

In an additional Wnt/Norrin activation assay, cultured human retinalendothelial cells can be exposed to Norrin or Wnt ligands in thepresence of LRP5 antibody or control antibody for 24-48 hours and thelevel of known Wnt reporter genes (ie. Axin-2 or PV-1) can be determinedby quantitative RT-PCR. In the control antibody situation, followingaddition of Norrin and Wnt ligands, the amount of Axin-2 RNA willincrease, while the amount of PV-1 RNA will decrease, relative to noligand addition. If the presence of the LRP5 antibody, potentiation ofNorrin signaling would result in a further increase in Axin-2 andconversely, decrease in PV-1. This assay can also be done in cellstreated with siRNA to decrease the expression of Tspan12. In cells withdiminished expression of Tspan12 there is no change in Axin-2 in thepresence of Norrin. If the LRP5 antibody, but not control antibody, isable to cause an increase in Axin-2 in the absence of Tspan12expression, then this antibody is considered to rescue the defect inFzd4/Norrin signaling resulting from loss of Tspan12.

D. Immunoconjugates

The invention also provides immunoconjugates comprising an anti-LRP5antibody herein conjugated to one or more cytotoxic agents, such aschemotherapeutic agents or drugs, growth inhibitory agents, toxins(e.g., protein toxins, enzymatically active toxins of bacterial, fungal,plant, or animal origin, or fragments thereof), or radioactive isotopes.

In one embodiment, an immunoconjugate is an antibody-drug conjugate(ADC) in which an antibody is conjugated to one or more drugs, includingbut not limited to a maytansinoid (see U.S. Pat. Nos. 5,208,020,5,416,064 and European Patent EP 0 425 235 B1); an auristatin such asmonomethylauristatin drug moieties DE and DF (MMAE and MMAF) (see U.S.Pat. Nos. 5,635,483 and 5,780,588, and 7,498,298); a dolastatin; acalicheamicin or derivative thereof (see U.S. Pat. Nos. 5,712,374,5,714,586, 5,739,116, 5,767,285, 5,770,701, 5,770,710, 5,773,001, and5,877,296; Hinman et al., Cancer Res. 53:3336-3342 (1993); and Lode etal., Cancer Res. 58:2925-2928 (1998)); an anthracycline such asdaunomycin or doxorubicin (see Kratz et al., Current Med. Chem.13:477-523 (2006); Jeffrey et al., Bioorganic & Med. Chem. Letters16:358-362 (2006); Torgov et al., Bioconj. Chem. 16:717-721 (2005); Nagyet al., Proc. Natl. Acad. Sci. USA 97:829-834 (2000); Dubowchik et al.,Bioorg. & Med. Chem. Letters 12:1529-1532 (2002); King et al., J. Med.Chem. 45:4336-4343 (2002); and U.S. Pat. No. 6,630,579); methotrexate;vindesine; a taxane such as docetaxel, paclitaxel, larotaxel, tesetaxel,and ortataxel; a trichothecene; and CC1065.

In another embodiment, an immunoconjugate comprises an antibody asdescribed herein conjugated to an enzymatically active toxin or fragmentthereof, including but not limited to diphtheria A chain, nonbindingactive fragments of diphtheria toxin, exotoxin A chain (from Pseudomonasaeruginosa), ricin A chain, abrin A chain, modeccin A chain,alpha-sarcin, Aleurites fordii proteins, dianthin proteins, Phytolacaamericana proteins (PAPI, PAPII, and PAP-S), momordica charantiainhibitor, curcin, crotin, sapaonaria officinalis inhibitor, gelonin,mitogellin, restrictocin, phenomycin, enomycin, and the tricothecenes.

In another embodiment, an immunoconjugate comprises an antibody asdescribed herein conjugated to a radioactive atom to form aradioconjugate. A variety of radioactive isotopes are available for theproduction of radioconjugates. Examples include At²¹¹, I¹³¹, I¹²⁵, Y⁹⁰,Re¹⁸⁶, Re¹⁸⁸, Sm¹⁵³, Bi²¹², P³², Pb²¹² and radioactive isotopes of Lu.When the radioconjugate is used for detection, it may comprise aradioactive atom for scintigraphic studies, for example tc99m or I123,or a spin label for nuclear magnetic resonance (NMR) imaging (also knownas magnetic resonance imaging, mri), such as iodine-123 again,iodine-131, indium-111, fluorine-19, carbon-13, nitrogen-15, oxygen-17,gadolinium, manganese or iron.

Conjugates of an antibody and cytotoxic agent may be made using avariety of bifunctional protein coupling agents such asN-succinimidyl-3-(2-pyridyldithio) propionate (SPDP),succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC),iminothiolane (IT), bifunctional derivatives of imidoesters (such asdimethyl adipimidate HCl), active esters (such as disuccinimidylsuberate), aldehydes (such as glutaraldehyde), bis-azido compounds (suchas bis (p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (suchas bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astoluene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin canbe prepared as described in Vitetta et al., Science 238:1098 (1987).Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent forconjugation of radionucleotide to the antibody. See WO94/11026. Thelinker may be a “cleavable linker” facilitating release of a cytotoxicdrug in the cell. For example, an acid-labile linker,peptidase-sensitive linker, photolabile linker, dimethyl linker ordisulfide-containing linker (Chari et al., Cancer Res. 52:127-131(1992); U.S. Pat. No. 5,208,020) may be used.

The immunuoconjugates or ADCs herein expressly contemplate, but are notlimited to such conjugates prepared with cross-linker reagentsincluding, but not limited to, BMPS, EMCS, GMBS, HBVS, LC-SMCC, MBS,MPBH, SBAP, SIA, SIAB, SMCC, SMPB, SMPH, sulfo-EMCS, sulfo-GMBS,sulfo-KMUS, sulfo-MBS, sulfo-SIAB, sulfo-SMCC, and sulfo-SMPB, and SVSB(succinimidyl-(4-vinylsulfone)benzoate) which are commercially available(e.g., from Pierce Biotechnology, Inc., Rockford, Ill., U.S.A).

E. Methods and Compositions for Diagnostics and Detection

In certain embodiments, any of the anti-LRP5 antibodies provided hereinis useful for detecting the presence of LRP5 in a biological sample. Theterm “detecting” as used herein encompasses quantitative or qualitativedetection. In certain embodiments, a biological sample comprises a cellor tissue, such as ocular tissue, including retinal tissue.

In one embodiment, an anti-LRP5 antibody for use in a method ofdiagnosis or detection is provided. In a further aspect, a method ofdetecting the presence of LRP5 in a biological sample is provided. Incertain embodiments, the method comprises contacting the biologicalsample with an anti-LRP5 antibody as described herein under conditionspermissive for binding of the anti-LRP5 antibody to LRP5, and detectingwhether a complex is formed between the anti-LRP5 antibody and LRP5.Such method may be an in vitro or in vivo method. In one embodiment, ananti-LRP5 antibody is used to select subjects eligible for therapy withan anti-LRP5 antibody, e.g. where LRP5 is a biomarker for selection ofpatients.

Exemplary disorders that may be diagnosed using an antibody of theinvention include retinopathies including proliferative diabeticretinopathy, CNV, AMD, diabetic and other ischemia-relatedretinopathies, DME, pathological myopia, von Hippel-Lindau disease,histoplasmosis of the eye, CRVO, BRVO, corneal neovascularization,retinal neovascularization, ROP, FEVR, Coats' disease, Norrie Disease,OPPG (Osteoporosis-Pseudoglioma Syndrome), subconjunctival hemorrhage,and hypertensive retinopathy.

In certain embodiments, labeled anti-LRP5 antibodies are provided.Labels include, but are not limited to, labels or moieties that aredetected directly (such as fluorescent, chromophoric, electron-dense,chemiluminescent, and radioactive labels), as well as moieties, such asenzymes or ligands, that are detected indirectly, e.g., through anenzymatic reaction or molecular interaction. Exemplary labels include,but are not limited to, the radioisotopes ³²P, ¹⁴C, ¹²⁵I, ³H, and ¹³¹I,fluorophores such as rare earth chelates or fluorescein and itsderivatives, rhodamine and its derivatives, dansyl, umbelliferone,luceriferases, e.g., firefly luciferase and bacterial luciferase (U.S.Pat. No. 4,737,456), luciferin, 2,3-dihydrophthalazinediones,horseradish peroxidase (HRP), alkaline phosphatase, β-galactosidase,glucoamylase, lysozyme, saccharide oxidases, e.g., glucose oxidase,galactose oxidase, and glucose-6-phosphate dehydrogenase, heterocyclicoxidases such as uricase and xanthine oxidase, coupled with an enzymethat employs hydrogen peroxide to oxidize a dye precursor such as HRP,lactoperoxidase, or microperoxidase, biotin/avidin, spin labels,bacteriophage labels, stable free radicals, and the like.

F. Pharmaceutical Formulations

Pharmaceutical formulations of an anti-LRP5 antibody as described hereinare prepared by mixing such antibody having the desired degree of puritywith one or more optional pharmaceutically acceptable carriers(Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980)),in the form of lyophilized formulations or aqueous solutions.Pharmaceutically acceptable carriers are generally nontoxic torecipients at the dosages and concentrations employed, and include, butare not limited to: buffers such as phosphate, citrate, and otherorganic acids; antioxidants including ascorbic acid and methionine;preservatives (such as octadecyldimethylbenzyl ammonium chloride;hexamethonium chloride; benzalkonium chloride; benzethonium chloride;phenol, butyl or benzyl alcohol; alkyl parabens such as methyl or propylparaben; catechol; resorcinol; cyclohexanol; 3-pentanol; and m-cresol);low molecular weight (less than about 10 residues) polypeptides;proteins, such as serum albumin, gelatin, or immunoglobulins;hydrophilic polymers such as polyvinylpyrrolidone; amino acids such asglycine, glutamine, asparagine, histidine, arginine, or lysine;monosaccharides, disaccharides, and other carbohydrates includingglucose, mannose, or dextrins; chelating agents such as EDTA; sugarssuch as sucrose, mannitol, trehalose or sorbitol; salt-formingcounter-ions such as sodium; metal complexes (e.g. Zn-proteincomplexes); and/or non-ionic surfactants such as polyethylene glycol(PEG). Exemplary pharmaceutically acceptable carriers herein furtherinclude insterstitial drug dispersion agents such as solubleneutral-active hyaluronidase glycoproteins (sHASEGP), for example, humansoluble PH-20 hyaluronidase glycoproteins, such as rHuPH20 (HYLENEX®,Baxter International, Inc.). Certain exemplary sHASEGPs and methods ofuse, including rHuPH20, are described in US Patent Publication Nos.2005/0260186 and 2006/0104968. In one aspect, a sHASEGP is combined withone or more additional glycosaminoglycanases such as chondroitinases.

Exemplary lyophilized antibody formulations are described in U.S. Pat.No. 6,267,958. Aqueous antibody formulations include those described inU.S. Pat. No. 6,171,586 and WO2006/044908, the latter formulationsincluding a histidine-acetate buffer.

The formulation herein may also contain more than one active ingredientsas necessary for the particular indication being treated, preferablythose with complementary activities that do not adversely affect eachother. For example, it may be desirable to further provide a VEGFantagonist (including, e.g., an anti-VEGF antibody or antibody fragment,e.g. ranibizumab, a soluble VEGF receptor or fragment thereof, e.g.aflibercept, or an aptamer, e.g. pegaptanib), a TSPAN12 agonist,plasmin, plasminogen, tissue plasminogen activator, triamcinolone, aTNF-α inhibitor, and/or dexamethasone. Such active ingredients aresuitably present in combination in amounts that are effective for thepurpose intended.

Active ingredients may be entrapped in microcapsules prepared, forexample, by coacervation techniques or by interfacial polymerization,for example, hydroxymethylcellulose or gelatin-microcapsules andpoly-(methylmethacylate) microcapsules, respectively, in colloidal drugdelivery systems (for example, liposomes, albumin microspheres,microemulsions, nano-particles and nanocapsules) or in macroemulsions.Such techniques are disclosed in Remington's Pharmaceutical Sciences16th edition, Osol, A. Ed. (1980).

Sustained-release preparations may be prepared. Suitable examples ofsustained-release preparations include semipermeable matrices of solidhydrophobic polymers containing the antibody, which matrices are in theform of shaped articles, e.g. films, or microcapsules.

The formulations to be used for in vivo administration are generallysterile. Sterility may be readily accomplished, e.g., by filtrationthrough sterile filtration membranes.

G. Therapeutic Methods and Compositions

Any of the anti-LRP5 antibodies provided herein may be used intherapeutic methods.

In one aspect, an anti-LRP5 antibody for use as a medicament isprovided. In further aspects, an anti-LRP5 antibody for use in treatingretinopathies including proliferative diabetic retinopathy, CNV, AMD,diabetic and other ischemia-related retinopathies, DME, pathologicalmyopia, von Hippel-Lindau disease, histoplasmosis of the eye, CRVO,BRVO, corneal neovascularization, retinal neovascularization, ROP, FEVR,Coats' disease, Norrie Disease, OPPG (Osteoporosis-PseudogliomaSyndrome), subconjunctival hemorrhage, and hypertensive retinopathy isprovided. In certain embodiments, an anti-LRP5 antibody for use in amethod of treatment is provided. In certain embodiments, the inventionprovides an anti-LRP5 antibody for use in a method of treating anindividual having a retinopathy including proliferative diabeticretinopathy, CNV, AMD, diabetic and other ischemia-relatedretinopathies, DME, pathological myopia, von Hippel-Lindau disease,histoplasmosis of the eye, CRVO, BRVO, corneal neovascularization,retinal neovascularization, ROP, FEVR, Coats' disease, Norrie Disease,OPPG (Osteoporosis-Pseudoglioma Syndrome), subconjunctival hemorrhage,or hypertensive retinopathy comprising administering to the individualan effective amount of the anti-LRP5 antibody. In one such embodiment,the method further comprises administering to the individual aneffective amount of at least one additional therapeutic agent, e.g., asdescribed below. In further embodiments, the invention provides ananti-LRP5 antibody for use in potentiating Norrin activity and/orpotentiating Norrin/Fzd4 signaling. In certain embodiments, theinvention provides an anti-LRP5 antibody for use in a method ofpotentiating Norrin activity and/or potentiating Norrin/Fzd4 signalingin an individual comprising administering to the individual an effectiveof the anti-LRP5 antibody to potentiate Norrin activity and/orpotentiate Norrin/Fzd4 signaling. An “individual” according to any ofthe above embodiments is preferably a human.

In a further aspect, the invention provides for the use of an anti-LRP5antibody in the manufacture or preparation of a medicament. In oneembodiment, the medicament is for treatment of a retinopathy includingproliferative diabetic retinopathy, CNV, AMD, diabetic and otherischemia-related retinopathies, DME, pathological myopia, vonHippel-Lindau disease, histoplasmosis of the eye, CRVO, BRVO, cornealneovascularization, retinal neovascularization, ROP, FEVR, Coats'disease, Norrie Disease, OPPG (Osteoporosis-Pseudoglioma Syndrome),subconjunctival hemorrhage, or hypertensive retinopathy. In a furtherembodiment, the medicament is for use in a method of treating aretinopathy including proliferative diabetic retinopathy, CNV, AMD,diabetic and other ischemia-related retinopathies, DME, pathologicalmyopia, von Hippel-Lindau disease, histoplasmosis of the eye, CRVO,BRVO, corneal neovascularization, retinal neovascularization, ROP, FEVR,Coats' disease, Norrie Disease, OPPG (Osteoporosis-PseudogliomaSyndrome), subconjunctival hemorrhage, or hypertensive retinopathycomprising administering to an individual having a retinopathy includingproliferative diabetic retinopathy, CNV, AMD, diabetic and otherischemia-related retinopathies, DME, pathological myopia, vonHippel-Lindau disease, histoplasmosis of the eye, CRVO, BRVO, cornealneovascularization, retinal neovascularization, ROP, FEVR, Coats'disease, Norrie Disease, OPPG (Osteoporosis-Pseudoglioma Syndrome),subconjunctival hemorrhage, or hypertensive retinopathy an effectiveamount of the medicament. In one such embodiment, the method furthercomprises administering to the individual an effective amount of atleast one additional therapeutic agent, e.g., as described below. In afurther embodiment, the medicament is for potentiating Norrin activityand/or potentiating Norrin/Fzd4 signaling. In a further embodiment, themedicament is for use in a method of potentiating Norrin activity and/orpotentiating Norrin/Fzd4 signaling in an individual comprisingadministering to the individual an amount effective of the medicament topotentiate Norrin activity and/or potentiate Norrin/Fzd4 signaling. An“individual” according to any of the above embodiments may be a human.

In a further aspect, the invention provides a method for treating aretinopathy including proliferative diabetic retinopathy, CNV, AMD,diabetic and other ischemia-related retinopathies, DME, pathologicalmyopia, von Hippel-Lindau disease, histoplasmosis of the eye, CRVO,BRVO, corneal neovascularization, retinal neovascularization, ROP, FEVR,Coats' disease, Norrie Disease, OPPG (Osteoporosis-PseudogliomaSyndrome), subconjunctival hemorrhage, or hypertensive retinopathy. Inone embodiment, the method comprises administering to an individualhaving such retinopathy including proliferative diabetic retinopathy,CNV, AMD, diabetic and other ischemia-related retinopathies, DME,pathological myopia, von Hippel-Lindau disease, histoplasmosis of theeye, CRVO, BRVO, corneal neovascularization, retinal neovascularization,ROP, FEVR, Coats' disease, Norrie Disease, OPPG(Osteoporosis-Pseudoglioma Syndrome), subconjunctival hemorrhage, orhypertensive retinopathy an effective amount of an anti-LRP5 antibody.In one such embodiment, the method further comprises administering tothe individual an effective amount of at least one additionaltherapeutic agent, as described below. An “individual” according to anyof the above embodiments may be a human.

In a further aspect, the invention provides a method for potentiatingNorrin activity and/or potentiating Norrin/Fzd4 signaling in anindividual. In one embodiment, the method comprises administering to theindividual an effective amount of an anti-LRP5 antibody to potentiateNorrin activity and/or potentiate Norrin/Fzd4 signaling. In oneembodiment, an “individual” is a human.

In a further aspect, the invention provides pharmaceutical formulationscomprising any of the anti-LRP5 antibodies provided herein, e.g., foruse in any of the above therapeutic methods. In one embodiment, apharmaceutical formulation comprises any of the anti-LRP5 antibodiesprovided herein and a pharmaceutically acceptable carrier. In anotherembodiment, a pharmaceutical formulation comprises any of the anti-LRP5antibodies provided herein and at least one additional therapeuticagent, e.g., as described below.

Antibodies of the invention can be used either alone or in combinationwith other agents in a therapy. For instance, an antibody of theinvention may be co-administered with at least one additionaltherapeutic agent. In certain embodiments, an additional therapeuticagent is a VEGF antagonist (including, e.g., an anti-VEGF antibody orantibody fragment, e.g. ranibizumab, a soluble VEGF receptor or fragmentthereof, e.g. aflibercept, or an aptamer, e.g. pegaptanib), a TSPAN12agonist, plasmin, plasminogen, tissue plasminogen activator,triamcinolone, a TNF-α inhibitor, and/or dexamethasone.

Such combination therapies noted above encompass combined administration(where two or more therapeutic agents are included in the same orseparate formulations), and separate administration, in which case,administration of the antibody of the invention can occur prior to,simultaneously, and/or following, administration of the additionaltherapeutic agent and/or adjuvant.

An antibody of the invention (and any additional therapeutic agent) canbe administered by any suitable means, including parenteral,intrapulmonary, and intranasal, and, if desired for local treatment,intraocular administration (e.g. intravitreal administration).Parenteral infusions include intramuscular, intravenous, intraarterial,intraperitoneal, or subcutaneous administration. Dosing can be by anysuitable route, e.g. by injections, such as intravitreal, depending inpart on whether the administration is brief or chronic. Various dosingschedules including but not limited to single or multipleadministrations over various time-points, bolus administration, andpulse infusion are contemplated herein.

Antibodies of the invention would be formulated, dosed, and administeredin a fashion consistent with good medical practice. Factors forconsideration in this context include the particular disorder beingtreated, the particular mammal being treated, the clinical condition ofthe individual patient, the cause of the disorder, the site of deliveryof the agent, the method of administration, the scheduling ofadministration, and other factors known to medical practitioners. Theantibody need not be, but is optionally formulated with one or moreagents currently used to prevent or treat the disorder in question. Theeffective amount of such other agents depends on the amount of antibodypresent in the formulation, the type of disorder or treatment, and otherfactors discussed above. These are generally used in the same dosagesand with administration routes as described herein, or about from 1 to99% of the dosages described herein, or in any dosage and by any routethat is empirically/clinically determined to be appropriate.

For the prevention or treatment of disease, the appropriate dosage of anantibody of the invention (when used alone or in combination with one ormore other additional therapeutic agents) will depend on the type ofdisease to be treated, the type of antibody, the severity and course ofthe disease, whether the antibody is administered for preventive ortherapeutic purposes, previous therapy, the patient's clinical historyand response to the antibody, and the discretion of the attendingphysician. The antibody is suitably administered to the patient at onetime or over a series of treatments. Depending on the type and severityof the disease, about 1 μg/kg to 15 mg/kg (e.g. 0.1 mg/kg-10 mg/kg) ofantibody can be an initial candidate dosage for administration to thepatient, whether, for example, by one or more separate administrations,or by continuous infusion. One typical daily dosage might range fromabout 1 μg/kg to 100 mg/kg or more, depending on the factors mentionedabove. For repeated administrations over several days or longer,depending on the condition, the treatment would generally be sustaineduntil a desired suppression of disease symptoms occurs. One exemplarydosage of the antibody would be in the range from about 0.05 mg/kg toabout 10 mg/kg. Thus, one or more doses of about 0.5 mg/kg, 2.0 mg/kg,4.0 mg/kg or 10 mg/kg (or any combination thereof) may be administeredto the patient. Such doses may be administered intermittently, e.g.every week or every three weeks (e.g. such that the patient receivesfrom about two to about twenty, or e.g. about six doses of theantibody). An initial higher loading dose, followed by one or more lowerdoses may be administered. However, other dosage regimens may be useful.The progress of this therapy is easily monitored by conventionaltechniques and assays.

It is understood that any of the above formulations or therapeuticmethods may be carried out using an immunoconjugate of the invention inplace of or in addition to an anti-LRP5 antibody.

H. Articles of Manufacture

In another aspect of the invention, an article of manufacture containingmaterials useful for the treatment, prevention and/or diagnosis of thedisorders described above is provided. The article of manufacturecomprises a container and a label or package insert on or associatedwith the container. Suitable containers include, for example, bottles,vials, syringes, IV solution bags, etc. The containers may be formedfrom a variety of materials such as glass or plastic. The containerholds a composition which is by itself or combined with anothercomposition effective for treating, preventing and/or diagnosing thecondition and may have a sterile access port (for example the containermay be an intravenous solution bag or a vial having a stopper pierceableby a hypodermic injection needle). At least one active agent in thecomposition is an antibody of the invention. The label or package insertindicates that the composition is used for treating the condition ofchoice. Moreover, the article of manufacture may comprise (a) a firstcontainer with a composition contained therein, wherein the compositioncomprises an antibody of the invention; and (b) a second container witha composition contained therein, wherein the composition comprises afurther cytotoxic or otherwise therapeutic agent. The article ofmanufacture in this embodiment of the invention may further comprise apackage insert indicating that the compositions can be used to treat aparticular condition. Alternatively, or additionally, the article ofmanufacture may further comprise a second (or third) containercomprising a pharmaceutically-acceptable buffer, such as bacteriostaticwater for injection (BWFI), phosphate-buffered saline, Ringer's solutionand dextrose solution. It may further include other materials desirablefrom a commercial and user standpoint, including other buffers,diluents, filters, needles, and syringes.

It is understood that any of the above articles of manufacture mayinclude an immunoconjugate of the invention in place of or in additionto an anti-LRP5 antibody.

III. Examples

The following are examples of methods and compositions of the invention.It is understood that various other embodiments may be practiced, giventhe general description provided above.

Example 1 Generation of Anti-LRP5 Antibodies

Library Sorting and Screening to Identify Anti-LRP5-E3/E4 Antibodies

We generated several LRP5 expression constructs, including thoseencoding the entire extracellular region, all four β-propeller domainsE1-4, each β-propeller domain alone, and E3-E4, and found that only theclone encoding the E3-E4 domains produced a significant quantity ofsoluble expressed protein. Therefore, we used biotinylated human LRP5domains E3-E4 generated in-house (E644-Q1263 of SEQ ID NO: 42) asantigen for library sorting. Nunc 96 well Maxisorp® immunoplates werecoated overnight at 4° C. with NeutrAvidin® (Fisher Scientific, #89890,10 μg/ml) or streptravidin (Fisher Scientific, #21125, 10 μg/ml) andwere blocked for 1 hour at room temperature with phage blocking bufferPBST (phosphate-buffered saline (PBS) and 1% (w/v) bovine serum albumin(BSA) and 0.05% (v/v) tween-20). Biotinylated LRP5-E3/E4 (10 μg/ml) wasthen captured onto the plate by NeutrAvidin®/streptravidin for 1 hour atroom temperature. Synthetic phage libraries of human antibodies (see,e.g., Lee et al., J. Immunol. Meth. 284:119-132, 2004, Liang et al., J.Molec. Biol. 366: 815-829, 2007) were added to antigen plates separatelyand incubated overnight at room temperature. The following dayantigen-coated plates were washed ten times with PBT (PBS with 0.05%Tween® 20), and bound phage were eluted with 50 mM HCl and 500 mM NaClfor 30 minutes and neutralized with an equal volume of 1 M Tris base(pH7.5). Recovered phages were amplified in E. coli XL-1 Blue cells.During the subsequent selection rounds, incubation of antibody phagewith the antigen-coated plates was reduced to 2-3 hours, and thestringency of plate washing was gradually increased.

After 6 rounds of panning, significant enrichment was observed. 96clones were picked each from library track to determine whether theyspecifically bind to human LRP5E3/E4. The variable regions of theseclones were PCR sequenced to identify unique sequence clones.

The phage supernatant was diluted 1:5 in ELISA (enzyme linkedimmunosorbent assay) buffer (PBS with 0.5% BSA, 0.05% Tween® 20) in 100μl total volume and was transferred to the target protein coated plates(1 μg/ml LRP5E3/E4 directly coated overnight) orneutravidin/streptavidin coated plate (5 μg/ml of each protein). Theplate was gently shaken for 1 hour to allow phage to bind to theprotein-coated plates. The plate was washed ten times with PBS-0.05%Tween® 20. The binding was quantified by adding horseradish peroxidase(HRP)-conjugated anti-M13 antibody in ELISA buffer (1:5000) andincubated for 30 minutes at room temperature. The plates were washed tentimes with PBS-0.05% Tween® 20. Next, 100 μl/well of a 1:1 ratio of3,3′,5,5′-tetramethylbenzidine (TMB) Peroxidase substrate and PeroxidaseSolution B (H₂O₂) (Kirkegaard-Perry Laboratories (Gaithersburg, Md.))was added to the well and incubated for 5 minutes at room temperature.The reaction was stopped by adding 100 μl 0.1M phosphoric Acid (H₃PO₄)to each well and allowed to incubate for 5 minutes at room temperature.The OD (optical density) of the yellow color in each well was determinedusing a standard ELISA plate reader at 450 nm. The OD reduction (%) wascalculated by the following equation:OD_(450nm) reduction (%)=[(OD_(450nm) of wells withcompetitor)/(OD_(450nm) of well with no competitor)]*100

Clones that had the OD_(450nm) at least 5 fold higher to LRP5E3/E4 thanbackground were picked and reformatted into full length human IgG1 bycloning V_(L) and V_(H) regions of individual clones into the LPG3 andLPG4 vector respectively. These clones were subsequently transientlyexpressed in mammalian CHO cells, and purified with a protein A column.

Construct Libraries and Panning Strategy for Affinity Improvement ofClones Derived from the Synthetic Phage Libraries

For each clone that showed promising cell-based assay activity, YW629.42and YW629.51, phagemid containing 4 stop codons (TAA) in CDR L3 anddisplaying monovalent Fab on the surface of M13 bacteriophage wasgenerated. These phagemids served as the templates for Kunkelmutagenesis for the construction of affinity maturation libraries. Foraffinity maturation, soft randomization strategy was used, wheremutagenic DNA was synthesized with 70-10-10-10 mixtures of basesfavoring the wild type nucleotides to obtain the mutation rate ofapproximately 50% at the selected positions (Gallop et al., Journal ofMedicinal Chemistry 37:1233-1251 (1994)). Four different combinations ofCDR loops, H1/L3, H2/L3, H3/L3, and L1/L2/L3 were selected forrandomization.

For affinity improvement selection, in-house generated LRP5E3/E4 wasfirst biotinylated under limiting reagent condition. Phage librarieswere subjected to six rounds of solution sorting with increasingstringency. For the first round of solution sorting, 3 O.D./ml in 1% BSAand 0.05% Tween® 20 of phage input were incubated to plates pre-coatedwith LRP5E3/E4 for 3 hours. The wells were washed with PBS-0.05% Tween®20 ten times. Bound phage was eluted with 150 μl/well 50 mM HCl, 500 mMKCl for 30 minutes, and subsequently neutralized by 50 μl/well of 1MTris pH8, titered, and propagated for the next round. For subsequentrounds, panning of the phage libraries was done in solution phase, wherephage library was incubated with initial concentration of 100 nMbiotinylated target protein (the concentration is based on parentalclone phage IC50 value) in 100 μl SuperBlock buffer (PierceBiotechnology) for 2 hours at room temperature. The mixture was furtherdiluted 10× with SuperBlock, and 100 μl/well was applied toNeutrAvidin®-coated wells (10 μg/ml) for 30 minutes at room temperaturewith gentle shaking To determine background binding, control wellscontaining phage were captured on neutravidin-coated plates. Bound phagewas then washed, eluted and propagated as described for first round.Five more rounds of solution sorting were carried out together withincreasing selection stringency. The first couple rounds of which is foron-rate selection by decreasing biotinylated target proteinconcentration from 100 nM to 0.5 nM, and the last two rounds of which isfor off-rate selection by adding excess amounts of non-biotinylatedtarget protein (300 to 1000 fold more) to compete off weaker binders atroom temperature.

High Throughput Affinity Screening ELISA (Single Spot Competition)

Colonies were picked from the sixth round of panning for screening.Colonies were grown overnight at 37° C. in 1 ml/well of 2YT media with50 μg/ml carbenicillin and 1×10¹⁰/ml M13KO7 in 96-well plate (Falcon).From the same plate, a colony of XL-1 infected parental phage wasincluded as control. 96-well Nunc Maxisorp® plates were coated with 100μl/well of LRP5E3/E4 (0.5 μg/ml) in PBS at 4° C. overnight. The plateswere blocked with 150 μl of 1% BSA and 0.05% Tween® 20 in PBS 20 for 1hour.

35 μl of the phage supernatant was diluted with to 75 μl of in ELISA(enzyme linked immunosorbent assay) buffer (PBS with 0.5% BSA, 0.05%Tween® 20) with or without 5 nM LRP5E3/4 and let incubate for 1 hour atroom temperature in an F plate (NUNC). 95 μl of mixture was transferredside by side to the antigen-coated plates. The plate was gently shakenfor 15 min and was washed ten times with PBS-0.05% Tween® 20. Thebinding was quantified by adding horseradish peroxidase (HRP)-conjugatedanti-M13 antibody in ELISA buffer (1:2500) and incubated for 30 minutesat room temperature. The plates were washed with PBS-0.05% Tween® 20 tentimes. Next, 100 μl/well of Peroxidase substrate was added to the welland incubated for 5 minutes at room temperature. The reaction wasstopped by adding 100 μl 0.1M Phosphoric Acid (H₃PO₄) to each well andallowed to incubate for 5 minutes at room temperature. The O.D. (opticaldensity) of each well was determined using a standard ELISA plate readerat 450 nm. In comparison to the OD_(450nm) reduction (%) of the well ofparental phage (100%), clones that had the OD_(450nm) reduction (%)lower than 50% were picked for sequence analysis. Unique clones wereselected for phage preparation to determine binding affinity (phageIC50) against target antigen LRP5E3/E4 by comparison to parental clone.Clone that showed most affinity-improvement were reformatted into humanIgG1 for antibody production and further BIAcore™ binding kineticanalysis and other in vitro or in vivo assays. The variable domainsequences for certain antibodies that were identified by this processare shown in FIGS. 4 and 5. In this specification the prefixes “YW629”and “P6C” may be used interchangeably. Therefore, e.g., the antibodydescribed as YW629.51.61 is the same as P6C.51.61.

Characterization of Anti-LRP5 Antibodies (BIAcore)

Binding affinities of anti-LRP5E3/E4 IgGs were measured by SurfacePlasmon Resonance (SPR) using a BIAcore™-T100 instrument. Anti-LRP5E3/E4human IgGs were captured by mouse anti-human Fc antibody (GE Healthcare,cat# BR-1008-39) coated on CM5 biosensor chips to achieve approximately200 response units (RU). For kinetics measurements, two-fold serialdilutions (500 nM to 0.245 nM) of human LRP5E3/E4 (GNE) were injected inHBS-P buffer (10 mM HEPES, pH 7.4, 0.15 M NaCl, 0.005% surfactant P20)at 25° C. with a flow rate of 30 μl/min. Association rates (k_(on)) anddissociation rates (k_(off)) were calculated using a simple one-to-oneLangmuir binding model (BIAcore Evaluation Software version 2.0.2). Theequilibrium dissociation constant (K_(D)) was calculated as the ratiok_(off)/k_(on). The results of this analysis for the antibodies in FIGS.4 and 5 are shown in Table 2 below.

TABLE 2 BIAcore analysis of anti-LRP5 antibodies Ligand ka (1/Ms) kd(1/s) KD (M) YW629.42 2.26 × 10⁴ 1.16 × 10⁻³ 5.16 × 10⁻⁸ YW629.42.573.01 × 10⁴ 1.63 × 10⁻⁴ 5.42 × 10⁻⁹ YW629.42.58 3.13 × 10⁴ 8.69 × 10⁻⁵2.78 × 10⁻⁹ YW629.42.65 3.79 × 10⁴ 9.63 × 10⁻⁵ 2.54 × 10⁻⁹ YW629.51 2.37× 10⁵ 3.09 × 10⁻³ 1.30 × 10⁻⁸ YW629.51.13 3.27 × 10⁵ 3.69 × 10⁻⁴ 1.13 ×10⁻⁹ YW629.51.61 2.44 × 10⁵ 1.15 × 10⁻⁴ 4.70 × 10⁻¹⁰ YW629.51.63 3.37 ×10⁵ 1.99 × 10⁻⁴ 5.92 × 10⁻¹⁰ YW629.51.77 3.76 × 10⁵ 1.65 × 10⁻⁴ 4.38 ×10⁻¹⁰ YW629.51.78 3.78 × 10⁵ 7.24 × 10⁻⁵ 1.92 × 10⁻¹⁰ YW629.51.80 3.87 ×10⁵ 1.04 × 10⁻⁴ 2.68 × 10⁻¹⁰

Example 2 Identification of Antibodies with Norrin Pathway PotentiatingActivity

Norrin signals through a membrane complex comprising LRP5, Frizzled4(FZD4) and Tetraspanin12 (TSPAN12). Mutants have been identified in eachof Norrin (e.g. Norrin-C95R), FZD4 (e.g. FZD4-M157V) and TSPAN12 (e.g.TSPAN12-G188R), which exhibit signaling deficiencies. We tested theability of various LRP5 antibodies to impact Norrin-mediated signaling.

In 24-well plates, 1.6×10⁵ cells/well were transfected with DNA mixcontaining b-Catenin reporter mix (TOPFlash, pRL-CMV, andpCan-myc-lef-1), LRP5, and Fzd4 or Fzd4-M157V. Twenty-four hoursfollowing transfection, the indicated amount of each LRP5 antibody wasadded. One hour later, 125 ng/ml of recombinant Norrin was added towells as indicated. Following an additional 16-hour incubation at 37°C., cells were lysed and Firefly and Renilla luciferase expression wasmeasured using Promega Dual-Glo® Reagents. Firefly luciferase valueswere normalized to Renilla expression. Norrin activates reporter geneexpression by ˜5-fold relative to no ligand. Addition of increasingamounts of antibody potentiates Norrin activity to ˜10-fold at 0.1-1μg/ml in all antibodies tested (FIG. 1A). When Fzd4-M157V is substitutedfor Fzd4 in the transfection, Norrin activation is reduced to only2-fold. Addition of LRP5 antibodies rescues defective signaling tolevels mirroring wildtype Fzd4 (FIG. 1B). These data indicate thatanti-LRP5 antibodies potentiate Norrin/Fzd4 signaling and rescue theFzd4-M157V mutation.

3×10⁵ human retinal endothelial microvascular cells (HREMVC) were seededon a 6-well dish. The next day 10 μg/ml of the indicated antibody wasadded, followed by 1.25 μg/ml Norrin, one-hour later. After anadditional 24-hours the RNA was isolated for Q-PCR analysis of Norrintarget genes, PV-1 (down-regulated by Norrin) and Axin-2 (up-regulatedby Norrin). Addition of Norrin upregulates Axin-2 expression by˜1.6-fold and downregulates PV-1 by ˜0.7-fold, relative to no ligand.Addition of indicated LRP5 antibodies further upregulates Axin-2 to˜2-fold and downregulates PV-1 to ˜0.5-fold (FIG. 2A). 3×10⁵ HREMVC wereseeded on 6-well dishes. Once cells were attached (˜4-hours), they weretransfected with 100 nM control or Tspan12 siRNA using DharmaFECT®transfection reagent. The following day the cells were seeded into a24-well plate and treated with indicated antibody and ligand (as above).As indicated by measuring Axin-2 gene expression, knockdown of Tspan12prevents activation with Norrin. Addition of 10 μg/ml of the indicatedLRP-5 antibodies partially rescues this defective Norrin signaling (FIG.2B). These data indicate that LRP5 antibodies potentiate Norrin activityand rescue loss of Tspan12.

We next test the activity of the anti-LRP5 antibodies in vivo. Tspan12knockout (KO) and wild-type littermates were treated with 25 mg/kganti-gD (negative control antibody) or anti-LRP5 antibody (YW629.42)daily from P3-P14. On P15, the eyes were enucleated and retinas wereharvested for vascular staining with biotinylated isolectin B4. Retinaswere stained with streptavidin-AF488, wholemounted, and imaged usingconfocal microscopy. XY and Z projections were compiled from 1.6 micronstacks captured through the thickness of each retina. As expected,Tspan12 KO retina vessels stall in the superficial vascular plexus andform small pathological vascular clusters just below the ganglion celllayer. Treatment with P6C.42, but not control antibody anti-gD,partially rescues the Tspan12 KO vascular defect by promoting deep layervascularization and reducing abnormal vascular clustering (FIG. 3A). AtP15, Tspan12 KO mice fail to form an inner plexiform (IPL) vascular bedthat is typical in wildtype mice. Treatment with YW629.42 partiallyrestores the IPL vasculature as compared to similar region in anti-gDtreated mice. (n=3 animals/treatment group; FIG. 3B). These datademonstrate that an anti-LRP5 antibody partially rescues vasculardefects in the Tspan12 knockout mice in vivo.

Tspan12 KO and heterozygous littermates were also treated with 25 mg/kganti-gD or anti-LRP5 antibody (P6C.51.61). For data shown in FIG. 6A,mice were treated daily from P6-P15 and sacrificed on P16 (6mice/treatment group). The eyes were enucleated and retinas wereharvested for vascular staining with biotinylated isolectin B4. Retinaswere stained with streptavidin-AF488, wholemounted, and imaged usingconfocal microscopy. XY and Z projections were compiled from 1.6 micronstacks captured through the thickness of each retina. Tspan12+/− micedisplay a normal retinal vasculature consisting of three distinctvascular layers (FIG. 6A, left, scale bar 100 μm). As expected, retinavessels from Tspan12−/− mice, treated with control antibody anti-gD,stall in the superficial vascular plexus and form small pathologicalvascular clusters below the ganglion cell layer (FIG. 6A, center).Treatment with P6C.51.61 partially rescues the Tspan12 vascular defectby promoting deep layer vascularization and reducing abnormal vascularclustering (FIG. 6A, right). For the data shown in FIG. 6B, mice weretreated daily from P3-P15, followed by every other day from P15-P30 (8mice/treatment group). At P31, eyes were enucleated and retinas wereharvested and treated as described above. Vessels in the inner plexiformlayer (IPL) was imaged by confocal microscopy. The IPL of Tspan12+/−mice contains the typical healthy capillary network (FIG. 6B, left,scale bar 50 μm), whereas Tspan12−/− treated with anti-gD controlantibody fails to form a capillary network and develops abnormal vesselfragments in the IPL (FIG. 6B, center). Treatment with P6C.51.61partially restores the formation of capillary network in the IPL (FIG.6B, right).

We next tested anti-LRP5 antibodies in an oxygen-induced retinopathy(OIR) model, which recapitulates certain pathologic features of adultretinal vascular disorders, such as capillary dropout and pathologicangiogenesis in retinal vein occlusion and diabetic retinopathy. Themodel consists of 2 phases: a hyperoxic phase from postnatal days 7-12(P7-P12) that results in vasoobliteration in the central retina, and arelative hypoxic phase from P12-P17 that leads to pathologicangiogenesis. Briefly, during phase 1, P7 neonatal mice are placed in ahyperoxic chamber consisting of 75% oxygen for 5 days. During this phasethe existing retinal vasculature regresses, resulting in avasoobliteration around the optic nerve head at the center. During thesecond phase, P12 mice are raised in room air consisting of 20% oxygen.The central vasoobliteration leads to a hypoxic response that causespathologic angiogenesis. For data shown in FIG. 7A, C57B16/N mice weresubjected to the OIR procedure as described above. Mice were treatedwith 25 mg/kg of anti-gD (negative control antibody) or anti-LRP5antibody (PC6.51.61) daily from P12-P17. On P17, the eyes wereenucleated and retinas were harvested and stained with isolectin B4 asdescribed previously. The total retinal area, the vasoobliterated area(outlined in center), and the pathological vasculature were measuredusing Fiji imaging software. FIG. 7B shows analysis of the data anddespite the fact that there was no significant difference in the overallarea of the retina between treatment group, mice treated with P6C.51.61had significantly greater vascular regrowth within the vasoobliteratedarea than anti-gD treated littermates. FIG. 7C shows that the enhancedvascular regrowth in the P6C.51.61 treated animals was accompanied by atrend towards reduced pathological vessel formation relative to theanti-gD treated cohort. n=5 animals/treatment group.

Example 3 Analysis of Norrin Pathway Potentiating Activity of Anti-LRP5Antibodies

We performed experiments to understand the mechanism by which ouranti-LRP5 antibodies act on the Norrin pathway and its other components.In 24-well plates, 1.6×10⁵ cells/well were transfected with a mixture ofDNAs containing TOPFlash, pRL-CMV, and pCan-myc-lef-1, LRP5, FZD-4, andcDNA encoding the indicated ligands (Norrin, or Wnt7b, or Wnt3a).Sixteen hours after transfection, 10 μg/ml of P6C.61.51 antibody wasadded. Following an additional 16-hour incubation at 37° C., cells werelysed and Firefly and Renilla luciferase expression was measured usingPromega Dual-Glo® Reagents. Firefly luciferase values were normalized toRenilla expression. FIG. 8A shows that Norrin activates reporter geneexpression by ˜6-fold relative to no ligand and that addition of 10μg/ml of P6C.51.61 potentiates Norrin activity by 3-fold relative toNorrin alone. FIG. 7B shows experiments demonstrating that Wnt7bactivates luciferase expression by ˜20-fold in the absence of antibodyand 2-fold enhancement over Wnt7b by P6C.51.61. FIG. 7C shows that thepresence of Wnt3a activates luciferase expression by >40-fold in theabsence of antibody but this activity is significantly antagonized inthe presence of P6C.51.61. Taken together, these data show thatP6C.51.61 potentiates Norrin and Wnt7b signaling, but antagonizes Wnt3asignaling.

Fzd4_(M157V) and Norrin_(C95R) are mutations that occur in patients withFEVR spectrum disorders and these mutations lead to decreased clusteringin the Fzd4/LRP5/Norrin receptor complex (Junge et al. Cell 139:299-311(2009)). Junge et al. demonstrated that overexpression of TSPAN12 couldrescue the clustering defects associated with Fzd4_(M157V) andNorrin_(C95R) and restore signaling to wildtype levels. We testedwhether P6C.51.61 could cluster the receptor complex and similarlyrescue these mutations. In 24-well plates, 1.6×10⁵ cells/well weretransfected with a mixture of DNAs containing TOPFlash, pRL-CMV,pCan-myc-lef-1, LRP5, Fzd4 or FZD4M157V, and Norrin or Norrin_(C95R).Sixteen hours after transfection, 10 μg/ml of P6C.61.51 antibody wasadded as indicated. Following an additional 16-hour incubation at 37°C., cells were lysed and Firefly and Renilla luciferase expression wasmeasured using Promega Dual-Glo® Reagents. Firefly luciferase valueswere normalized to Renilla expression. FIG. 8A shows that Norrinactivates reporter gene expression by ˜6-fold relative to no ligand inthe presence of wild type Fzd4. Under these conditions, addition of 10μg/ml of P6C.51.61 potentiates Norrin activity by 3-fold relative toNorrin alone. When Fzd4_(M157V) is substituted for Fzd4 in thetransfection, Norrin activation is reduced to ˜2-fold relative to noligand. Addition of P6C.51.61 rescues the defective Fzd4_(M157V)signaling to levels mirroring wildtype Fzd4 (dotted line). FIG. 8B showsthat replacing Norrin with Norrin_(C95R) leads to a significant decreasein pathway activation in the absence of antibody but in the presence ofP6C.51.61, Norrin_(C95R) activity is restored to the level associatedwith wildtype Norrin (dotted line). These results demonstrate thatP6C.51.61 rescues mutations in receptor components that reduce receptorclustering.

We next tested the impact of antibody valency of activity. We found thatbivalent binding is required for anti-LRP5 potentiation of Norrinsignaling, but not inhibition of Wnt3a signaling. In 24-well plates,1.6×10⁵ cells/well were transfected with a mixture of DNAs containingTOPFlash, pRL-CMV, and pCan-myc-lef-1, LRP5, and FZD-4. Twenty-fourhours following transfection, the indicated amount of each LRP5 antibodywas added. One hour later, 125 ng/ml of recombinant Norrin or 200 ng/mlof Wnt3a was added. Following an additional 16-hour incubation at 37°C., cells were lysed and Firefly and Renilla luciferase expression wasmeasured using Promega Dual-Glo® Reagents. Firefly luciferase valueswere normalized to Renilla expression. FIG. 10A shows that Norrinactivates reporter gene expression by ˜8-fold relative to the controlwithout ligand. Addition of 10 μg/ml of bivalent LRP5 antibody (P6C.51)potentiates Norrin activity by >2 fold but addition of 10 μg/ml ofmonovalent (Fab) LRP5 antibody fails to potentiate Norrin signaling.FIG. 10B shows that anti-LRP5 antibody antagonizes Wnt3a signaling inthe presence of 10 μg/ml of either bivalent or monovalent LRP5. Thesedata suggest that the bivalent nature of the anti-LRP5 MAb is requiredfor clustering of the receptor complex, which is known to be requiredfor Norrin signaling.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, the descriptions and examples should not be construed aslimiting the scope of the invention. The disclosures of all patent andscientific literature cited herein are expressly incorporated in theirentirety by reference.

What is claimed is:
 1. An isolated nucleic acid encoding an antibodythat binds to Low-density lipoprotein receptor-related protein 5 (LRP5),wherein the antibody potentiates Norrin activity and/or Norrin/Fzd4(Frizzled4) signaling, wherein the antibody comprises (a) HVR-H1comprising the amino acid sequence GFTFSSYAMX₁, wherein X₁ is H or S(SEQ ID NO: 28), (b) HVR-H2 comprising the amino acid sequenceGX₁ISX₂X₃GX₄STYYADSVKG, wherein X₁ is A or G, X₂ is A or S, X₃ is P orS, X₄ is S or W (SEQ ID NO: 26), or SRISSNGGSTYYADSVKG (SEQ ID NO: 27),(c) HVR-H3 comprising the amino acid sequence YYRYAPYRSLGMDV (SEQ ID NO:23) or WIPQSYPFX₁SYKSGFDY, wherein X₁ is A or R (SEQ ID NO: 24), (d)HVR-L1 comprising the amino acid sequence RASQGISSYLA (SEQ ID NO: 29) orRASQX₁X₂X₃X₄YLA, wherein X₁ is A, G, S or V, X₂ is I or M, X₃ is F, G, Sor Y, and X₄ is G, S or Y (SEQ ID NO: 30); (e) HVR-L2 comprising theamino acid sequence AASSLQS (SEQ ID NO: 31) or DASX₁X₂ES, wherein X₁ isS or T and X₂ is L or R (SEQ ID NO: 32); and (f) HVR-L3 comprising theamino acid sequence QQYYX₁YPFT, wherein X₁ is L or S (SEQ ID NO: 33). 2.The nucleic acid of claim 1, wherein the antibody comprises (a) HVR-H1comprising the amino acid sequence GFTFSSYAMS (SEQ ID NO: 48), (b)HVR-H2 comprising the amino acid sequence GAISSSGSSTYYADSVKG (SEQ ID NO:49), (c) HVR-H3 comprising the amino acid sequence YYRYAPYRSLGMDV (SEQID NO: 23), (d) HVR-L1 comprising the amino acid sequence RASQGISSYLA(SEQ ID NO: 29); (e) HVR-L2 comprising the amino acid sequence AASSLQS(SEQ ID NO: 31); and (f) HVR-L3 comprising the amino acid sequenceQQYYSYPFT (SEQ ID NO: 47).
 3. The nucleic acid of claim 1, wherein theantibody comprises (a) HVR-H1 comprising the amino acid sequenceGFTFSSYAMS (SEQ ID NO: 48), (b) HVR-H2 comprising the amino acidsequence GAISAPGSSTYYADSVKG (SEQ ID NO: 50), (c) HVR-H3 comprising theamino acid sequence YYRYAPYRSLGMDV (SEQ ID NO: 23), (d) HVR-L1comprising the amino acid sequence RASQGISSYLA (SEQ ID NO: 29); (e)HVR-L2 comprising the amino acid sequence AASSLQS (SEQ ID NO: 31); and(f) HVR-L3 comprising the amino acid sequence QQYYSYPFT (SEQ ID NO: 47).4. The nucleic acid of claim 1, wherein the antibody comprises (a)HVR-H1 comprising the amino acid sequence GFTFSSYAMS (SEQ ID NO: 48),(b) HVR-H2 comprising the amino acid sequence GAISSPGWSTYYADSVKG (SEQ IDNO: 51), (c) HVR-H3 comprising the amino acid sequence YYRYAPYRSLGMDV(SEQ ID NO: 23), (d) HVR-L1 comprising the amino acid sequenceRASQGISSYLA (SEQ ID NO: 29); (e) HVR-L2 comprising the amino acidsequence AASSLQS (SEQ ID NO: 31); and (f) HVR-L3 comprising the aminoacid sequence QQYYSYPFT (SEQ ID NO: 47).
 5. The nucleic acid of claim 1,wherein the antibody comprises (a) HVR-H1 comprising the amino acidsequence GFTFSSYAMS (SEQ ID NO: 48), (b) HVR-H2 comprising the aminoacid sequence GGISSPGSSTYYADSVKG (SEQ ID NO: 52), (c) HVR-H3 comprisingthe amino acid sequence YYRYAPYRSLGMDV (SEQ ID NO: 23), (d) HVR-L1comprising the amino acid sequence RASQGISSYLA (SEQ ID NO: 29); (e)HVR-L2 comprising the amino acid sequence AASSLQS (SEQ ID NO: 31); and(f) HVR-L3 comprising the amino acid sequence QQYYLYPFT (SEQ ID NO: 53).6. The nucleic acid of claim 1, wherein the antibody comprises (a)HVR-H1 comprising the amino acid sequence GFTFSSYAMH (SEQ ID NO: 43),(b) HVR-H2 comprising the amino acid sequence SRISSNGGSTYYADSVKG (SEQ IDNO: 27), (c) HVR-H3 comprising the amino acid sequence WIPQSYPFRSYKSGFDY(SEQ ID NO: 54), (d) HVR-L1 comprising the amino acid sequenceRASQGISSYLA (SEQ ID NO: 29); (e) HVR-L2 comprising the amino acidsequence DASSLES (SEQ ID NO: 46); and (f) HVR-L3 comprising the aminoacid sequence QQYYSYPFT (SEQ ID NO: 47).
 7. The nucleic acid of claim 1,wherein the antibody comprises (a) HVR-H1 comprising the amino acidsequence GFTFSSYAMH (SEQ ID NO: 43), (b) HVR-H2 comprising the aminoacid sequence SRISSNGGSTYYADSVKG (SEQ ID NO: 27), (c) HVR-H3 comprisingthe amino acid sequence WIPQSYPFASYKSGFDY (SEQ ID NO: 44), (d) HVR-L1comprising the amino acid sequence RASQSIYYYLA (SEQ ID NO: 55); (e)HVR-L2 comprising the amino acid sequence DASSLES (SEQ ID NO: 46); and(f) HVR-L3 comprising the amino acid sequence QQYYSYPFT (SEQ ID NO: 47).8. The nucleic acid of claim 1, wherein the antibody comprises (a)HVR-H1 comprising the amino acid sequence GFTFSSYAMH (SEQ ID NO: 43),(b) HVR-H2 comprising the amino acid sequence SRISSNGGSTYYADSVKG (SEQ IDNO: 27), (c) HVR-H3 comprising the amino acid sequence WIPQSYPFASYKSGFDY(SEQ ID NO: 44), (d) HVR-L1 comprising the amino acid sequenceRASQVIYGYLA (SEQ ID NO: 56); (e) HVR-L2 comprising the amino acidsequence DASTRES (SEQ ID NO: 57); and (f) HVR-L3 comprising the aminoacid sequence QQYYSYPFT (SEQ ID NO: 47).
 9. The nucleic acid of claim 1,wherein the antibody comprises (a) HVR-H1 comprising the amino acidsequence GFTFSSYAMH (SEQ ID NO: 43), (b) HVR-H2 comprising the aminoacid sequence SRISSNGGSTYYADSVKG (SEQ ID NO: 27), (c) HVR-H3 comprisingthe amino acid sequence WIPQSYPFASYKSGFDY (SEQ ID NO: 44), (d) HVR-L1comprising the amino acid sequence RASQGIFYYLA (SEQ ID NO: 58); (e)HVR-L2 comprising the amino acid sequence DASTLES (SEQ ID NO: 59); and(f) HVR-L3 comprising the amino acid sequence QQYYSYPFT (SEQ ID NO: 47).10. The nucleic acid of claim 1, wherein the antibody comprises (a)HVR-H1 comprising the amino acid sequence GFTFSSYAMH (SEQ ID NO: 43),(b) HVR-H2 comprising the amino acid sequence SRISSNGGSTYYADSVKG (SEQ IDNO: 27), (c) HVR-H3 comprising the amino acid sequence WIPQSYPFASYKSGFDY(SEQ ID NO: 44), (d) HVR-L1 comprising the amino acid sequenceRASQAIYSYLA (SEQ ID NO: 60); (e) HVR-L2 comprising the amino acidsequence DASSLES (SEQ ID NO: 46); and (f) HVR-L3 comprising the aminoacid sequence QQYYSYPFT (SEQ ID NO: 47).
 11. The nucleic acid of claim1, wherein the antibody comprises (a) HVR-H1 comprising the amino acidsequence GFTFSSYAMH (SEQ ID NO: 43), (b) HVR-H2 comprising the aminoacid sequence SRISSNGGSTYYADSVKG (SEQ ID NO: 27), (c) HVR-H3 comprisingthe amino acid sequence WIPQSYPFASYKSGFDY (SEQ ID NO: 44), (d) HVR-L1comprising the amino acid sequence RASQVMGYYLA (SEQ ID NO: 45); (e)HVR-L2 comprising the amino acid sequence DASSLES (SEQ ID NO: 46); and(f) HVR-L3 comprising the amino acid sequence QQYYSYPFT (SEQ ID NO: 47).12. The nucleic acid of claim 1, wherein the antibody comprises (a)HVR-H1 comprising the amino acid sequence GFTFSSYAMH (SEQ ID NO: 43),(b) HVR-H2 comprising the amino acid sequence SRISSNGGSTYYADSVKG (SEQ IDNO: 27), (c) HVR-H3 comprising the amino acid sequence WIPQSYPFASYKSGFDY(SEQ ID NO: 44), (d) HVR-L1 comprising the amino acid sequenceRASQGISSYLA (SEQ ID NO: 29); (e) HVR-L2 comprising the amino acidsequence DASSLES (SEQ ID NO: 46); and (f) HVR-L3 comprising the aminoacid sequence QQYYSYPFT (SEQ ID NO: 47).
 13. The nucleic acid of claim1, wherein the antibody is a monoclonal antibody.
 14. The nucleic acidof claim 1, wherein the antibody is a human, humanized, or chimericantibody.
 15. The nucleic acid of claim 1, wherein the antibody is anantibody fragment that binds LRP5.
 16. The nucleic acid of claim 1,wherein the antibody is a full length IgG1 antibody.
 17. The nucleicacid of claim 1, wherein the antibody further comprises one or moreheavy chain variable domain framework sequences selected from the groupconsisting of SEQ ID NO: 34-37.
 18. An isolated nucleic acid encoding anantibody comprising a VH sequence of one of SEQ ID NOs: 1 to 11 and a VLsequence of one of SEQ ID NOs: 12 to
 22. 19. The nucleic acid of claim18, wherein the antibody comprises the VH sequence of SEQ ID NO: 1 andthe VL sequence of SEQ ID NO:
 12. 20. The nucleic acid of claim 18,wherein the antibody comprises the VH sequence of SEQ ID NO: 2 and theVL sequence of SEQ ID NO:
 13. 21. The nucleic acid of claim 18, whereinthe antibody comprises the VH sequence of SEQ ID NO: 3 and the VLsequence of SEQ ID NO:
 14. 22. The nucleic acid of claim 18, wherein theantibody comprises the VH sequence of SEQ ID NO: 4 and the VL sequenceof SEQ ID NO:
 15. 23. The nucleic acid of claim 18, wherein the antibodycomprises the VH sequence of SEQ ID NO: 5 and the VL sequence of SEQ IDNO:
 16. 24. The nucleic acid of claim 18, wherein the antibody comprisesthe VH sequence of SEQ ID NO: 6 and the VL sequence of SEQ ID NO: 17.25. The nucleic acid of claim 18, wherein the antibody comprises the VHsequence of SEQ ID NO: 7 and the VL sequence of SEQ ID NO:
 18. 26. Thenucleic acid of claim 18, wherein the antibody comprises the VH sequenceof SEQ ID NO: 8 and the VL sequence of SEQ ID NO:
 19. 27. The nucleicacid of claim 18, wherein the antibody comprises the VH sequence of SEQID NO: 9 and the VL sequence of SEQ ID NO:
 20. 28. The nucleic acid ofclaim 18, wherein the antibody comprises the VH sequence of SEQ ID NO:10 and the VL sequence of SEQ ID NO:
 21. 29. The nucleic acid of claim18, wherein the antibody comprises the VH sequence of SEQ ID NO: 11 andthe VL sequence of SEQ ID NO:
 22. 30. A host cell comprising the nucleicacid of claim 1 or
 18. 31. A method of producing an antibody comprisingculturing the host cell of claim 30 so that the antibody is produced.